Briefing document & Podcast: Poland E-Invoicing, E-Reporting and KSeF Mandate

Last update: January 24, 2026

SUMMARY

1. Introduction to KSeF

Poland is implementing a mandatory electronic invoicing (e-invoicing) and reporting system, KSeF, aiming to digitalize VAT administration, combat fraud, and streamline tax processes. KSeF is a centralized clearance platform where all in-scope invoices are issued, validated, and stored by the Ministry of Finance.

2. Scope of the Mandate

The KSeF mandate is broad, covering most VAT-applicable transactions in Poland, with specific inclusions and limited exceptions:

Domestic B2B (Business-to-Business): Mandatory for all invoices between Polish businesses. From 2026, “a paper or PDF invoice will no longer be a valid legal invoice for B2B transactions – it must be a structured e-invoice in KSeF.”
Domestic B2C (Business-to-Consumer): Not mandated (optional). Businesses can continue issuing traditional receipts or paper/PDF invoices. Voluntary use with a QR code for consumer access is supported.
Domestic B2G (Business-to-Government): Mandated for receipt by public institutions (since 2019 via PEF portal); KSeF will be available for issuance by businesses and “will integrate with PEF.”
Cross-border Transactions: Intra-EU B2B (Exports from Poland): Mandatory. Polish sellers must issue invoices via KSeF, even if a copy is sent to the foreign buyer.
Intra-EU B2B (Imports into Poland): Not issued via KSeF. Foreign suppliers’ invoices are outside KSeF; Polish buyers account for VAT and report these in their SAF-T (JPK_VAT) with specific codes (“BFK” for foreign invoices).
Extra-EU Exports: Mandatory. Polish exporters must issue invoices via KSeF (VAT zero-rated).
Extra-EU Imports: Generally outside KSeF scope, handled via customs and VAT returns.
Special Transaction Scenarios (In-Scope):Self-billing: Allowed and in-scope. Buyers can issue structured invoices through KSeF on behalf of authorized sellers via the ZAW-FA form.
Triangulation and Chain Transactions: Each invoice leg issued by a Polish VAT-registered entity must go through KSeF. Foreign-issued invoices in a chain are reported in SAF-T.
Special VAT Regimes (e.g., Margin Schemes): Invoices under these schemes must be issued via KSeF, including notes for the specific regime (e.g., “VAT marża”).
Notable Exclusions (Document-Type Based): Invoices issued under the EU One-Stop-Shop (OSS) or Import OSS regimes, toll motorway tickets/receipts, passenger transport tickets, and receipts with a buyer’s NIP (tax ID) under PLN 450 (until end of 2026).

3. Taxable Persons in Scope

The mandate covers “all taxable persons (VAT taxpayers) who are required to issue invoices under Polish VAT law,” regardless of size or location, with very limited exceptions:

Established Polish Entities: All VAT-registered businesses in Poland (corporations, SMEs, micro-businesses, sole proprietors, etc.), including those that are VAT-exempt but issue invoices, are covered.
Non-established Entities with Polish VAT Registration: Foreign businesses with a Polish VAT number (e.g., without a Fixed Establishment, FE) must use KSeF for invoices issued under that Polish VAT number by April 1, 2026. If a foreign entity has an FE in Poland, it is definitively obliged.
Exemptions: No blanket exemption based on size or sector. Micro-taxpayers receive temporary deferrals (see Timeline).

4. Implementation Timeline

Poland’s KSeF rollout follows a phased schedule:

Voluntary/Pilot Phase: January 1, 2022 – January 2026. KSeF was available for voluntary use, with incentives like faster VAT refunds.
Mandatory Go-Live (Phased Rollout):February 1, 2026: Mandatory for “Large taxpayers” (companies exceeding PLN 200 million gross turnover in 2024). Crucially, “All businesses, regardless of size, must be ready to receive invoices via KSeF starting 1 Feb 2026.”
April 1, 2026: Mandatory for “All other entrepreneurs” (remaining VAT-registered businesses, including foreign VAT-registered companies without an FE).
January 1, 2027: Mandatory for “Micro taxpayers” (monthly sales invoicing not exceeding PLN 10,000 gross).
Grace Period (Enforcement Delay): February 2026 – December 2026. “No financial penalties will be imposed for not using KSeF correctly” during this period. Transitional allowances permit certain small businesses or transactions to temporarily use non-KSeF methods.
Full Enforcement: January 1, 2027. Full mandatory scope, with penalties beginning.

5. Technical & Functional Requirements

KSeF is a central clearance system based on specific technical standards:

E-invoice Format: All invoices must be submitted in a structured XML format conforming to the official Polish “FA(3)” schema. PDF, Word, or scanned invoices are not valid legal invoices within KSeF.
E-reporting: KSeF integrates with the existing monthly JPK_VAT (SAF-T) file. Each sales and purchase record in SAF-T will include KSeF numbers or specific codes (“OFF”, “BFK”, “DI”) explaining why a KSeF number is absent.
Validation Rules: The KSeF platform performs automatic validation on each submitted invoice. Invoices must conform to the FA(3) schema and contain all mandatory data elements (seller/buyer IDs, dates, line items, VAT rates, etc.). Rejected invoices are not considered issued.
Digital Signature / Integrity: Individual invoices do not require a separate digital signature. Authenticity and integrity are ensured by KSeF itself through secure transmission, validation, and assigning a unique, tamper-proof KSeF ID and timestamp.
Real-Time Processing & Deadlines: KSeF operates as a “real-time clearance system.” An invoice is considered “issued” the moment it is successfully uploaded to KSeF and validated. Transmission is expected immediately upon issuance, with an exception for offline mode.
Offline (Contingency) Workflow: In cases of KSeF unavailability or taxpayer connectivity issues, invoices can be issued in “offline24” mode (with a special flag and QR code) and must be uploaded to KSeF once connectivity is restored (generally “by the next business day”).

6. Transmission & Workflow

Central Clearance Platform: KSeF is the single, centralized government platform for all e-invoices. Suppliers transmit invoices to KSeF (via API or government applications), KSeF validates and clears them, and buyers retrieve them from KSeF. “By law, delivering the invoice to KSeF counts as delivery to the buyer.”
Transmission Channels: The primary channel is the KSeF API, used for system-to-system integration. For smaller entities, the Ministry offers a web portal (app.ksef.mf.gov.pl) and mobile/desktop apps. Authentication uses digital certificates, Polish e-IDs, qualified electronic seals, or one-time tokens.
Workflow for Buyers: Buyers must actively retrieve invoices from KSeF. Many will use automated fetch mechanisms or periodically check the web portal. Delegation of access to accountants or software providers is possible via the ZAW-FA authorization.
Security: Authentication is required for all KSeF users, and transmissions use encrypted TLS connections, ensuring secure access and preventing unauthorized data access.

7. Self-Billing

KSeF fully supports self-billing, where the buyer issues the invoice on behalf of the seller:

Procedure: The seller must explicitly authorize the buyer in the KSeF system using the ZAW-FA notification. Once authorized, the buyer transmits the invoice through KSeF, indicating it’s issued on the seller’s behalf.
Content: Self-billed invoices adhere to the FA(3) schema and contain all mandatory elements, plus a notation indicating it’s self-billed.
Delivery: Once submitted by the buyer, the invoice is delivered to both the seller’s and buyer’s KSeF accounts.

8. Triangulation & Special Scenarios

Complex VAT scenarios are handled within the standard KSeF framework:

Triangulation and Chain Transactions: Any invoice issued by a Polish entity in a triangulation or chain transaction must go through KSeF. Foreign-issued invoices are outside KSeF and reported via SAF-T.
Cross-border Reverse Charge: Invoices from foreign suppliers where a Polish business applies reverse charge are outside KSeF and reported in SAF-T. Domestic reverse charge invoices, however, must be issued via KSeF.
Zero-rated/Exempt Supplies: These invoices are fully in scope and must be issued through KSeF, with appropriate VAT rates (0% or “ZW” for exempt) and legal basis indicated.

9. Archiving & Retention

KSeF significantly changes archiving obligations:

Central Storage: “The Ministry of Finance will store all e-invoices in the central system for the legally required period.” Taxpayers are relieved of the obligation to archive KSeF invoices themselves.
Retention Period: KSeF is expected to store e-invoices for at least 10 years, aligning with common retention practices.
Integrity, Authenticity, Readability: KSeF guarantees these aspects. The system’s unique IDs and timestamps ensure content integrity, and a human-readable display of the XML is available.
Audit Access: Tax authorities have direct access to all KSeF invoices, streamlining audits.

10. Penalties & Enforcement

Poland’s enforcement regime for KSeF is strict but phased:

Grace Period (2026): “No financial penalties will be imposed for not using KSeF correctly” from February 1, 2026, to December 31, 2026. Authorities will focus on education and assistance.
Post-2026 Penalties: From January 1, 2027, “failing to issue an invoice through KSeF when required can trigger heavy fines – up to 100% of the VAT on that invoice.” For non-VAT invoices, penalties can be up to 18.7% of the gross amount. Penalties also apply for late submission of offline invoices. Existing Penal Fiscal Code provisions may apply for deliberate non-compliance.
Buyer Impact: While no direct penalties for buyers, failure by suppliers to issue valid KSeF invoices could lead to buyers losing their right to deduct VAT.

11. Pre-Filled VAT Returns

Current Status: Poland “currently does not provide pre-filled VAT returns to taxpayers.” The obligation remains for taxpayers to compile and submit their monthly/quarterly JPK_VAT returns.
Future Outlook: KSeF collects real-time data that “could pave the way for future pre-filled return initiatives,” aligning with broader EU digital tax ambitions (e.g., ViDA). However, no immediate plans or timelines for implementing this have been announced.

12. Impact on SMEs and Startups

KSeF will have a significant impact on smaller businesses, presenting both challenges and benefits:

Challenges:Initial Costs: Software upgrades, integration, or subscription services may be required.
Process Changes: Learning new systems, training staff, and adjusting workflows (e.g., manual data entry to digital XML creation) create an initial administrative burden.
Readiness: Many SMEs might be unprepared, facing a rush to comply by their respective deadlines.
Benefits:Phased Rollout and Free Tools: The staggered timeline and government-provided free web/mobile applications ease the transition and reduce initial costs for SMEs.
Faster VAT Refunds: KSeF users are entitled to VAT refunds in 40 days instead of the standard 60, improving cash flow for cash-sensitive businesses.
Reduced Administrative Burden (Long-Term): Automation of data entry, elimination of manual archiving, and reduced errors can lead to long-term efficiency gains.
Improved Compliance and Audit Process: Instant validation reduces errors, and direct access for auditors may lead to fewer or quicker audits.
Digitalization: Forces SMEs to modernize invoicing, potentially improving overall efficiency and competitiveness.

13. Critical Dates & Next Steps

Now – Jan 2026: Final preparations for large companies, including software compatibility checks, obtaining KSeF certificates, and staff training. All companies should prepare to receive invoices via KSeF.
Feb 1, 2026: Mandatory go-live for large enterprises; all businesses must be ready to receive KSeF invoices.
Apr 1, 2026: Mandatory go-live for all other VAT-registered businesses.
Throughout 2026: Grace period with no penalties. Businesses should use this time to stabilize processes and address issues.
Jan 1, 2027: Full enforcement begins, including for micro-businesses, with penalties for non-compliance.

Further Resources

For comprehensive and up-to-date information on global VAT and customs regulations, including e-invoicing mandates and e-reporting rules, professionals can visit VATupdate.com.

INDEPTH ANALYSIS

1. Scope of the Mandate

Poland’s national e-invoicing mandate (via the KSeF system) covers virtually all VAT-applicable transactions in the country, with only a few exceptions. Key points about transaction scope:

Domestic B2B (Business-to-Business): Mandatory. All invoices between Polish businesses must be issued through the KSeF platform. This includes standard sales of goods and services where both supplier and customer are registered for Polish VAT. From 2026 onward, a paper or PDF invoice will no longer be a valid legal invoice for B2B transactions – it must be a structured e-invoice in KSeF (unless a specific exemption applies). [dudkowiak.com]
Domestic B2C (Business-to-Consumer): Not mandated (optional). Sales to consumers are generally outside the mandatory scope. Businesses may continue to issue traditional receipts or paper/PDF invoices for B2C. However, they can use KSeF voluntarily for B2C invoices if they wish (the system supports it, e.g. with a QR code for consumer access). Importantly, public law does not force B2C invoice issuance via KSeF – it remains at the discretion of the supplier. (Note: Polish law doesn’t usually require an invoice for a consumer sale unless the consumer requests one, or a specific case like a car sale – if an invoice is issued to a consumer, it can be either through KSeF or by old methods.) [bdo.global] [ec.europa.eu], [taxnews.ey.com]
Domestic B2G (Business-to-Government): Mandated for receipt, optional for issuance. Since 2019, Polish public institutions must accept structured e-invoices (via the separate PEF portal) in line with EU Directive 2014/55/EU. Under the KSeF reform, companies dealing with government have two paths: they may use the existing PEF (which is PEPPOL-based) or send invoices via KSeF (which will integrate with PEF). There isn’t a new legal obligation for suppliers to use KSeF for B2G, because public bodies already have to accept e-invoices; however, in practice KSeF will be available to streamline even B2G invoicing. Essentially, if a business issues an invoice to a Polish government entity, that invoice can be routed through KSeF as part of the general mandate (the government entity will retrieve it from KSeF, or via integration with PEF). The B2G scenario is thus covered by the same B2B mandate for the supplier side, even though it was not separately mandated before. [ec.europa.eu] [ec.europa.eu], [ec.europa.eu]
Intra-EU B2B (Cross-border within EU): Exports (dispatches) from Poland: Mandatory; Imports (acquisitions) into Poland: reported but not issued via KSeF. If a Polish company sells to a business in another EU country (an intra-Community supply of goods or cross-border service), the Polish seller must issue the invoice via KSeF. This is treated like any other outbound B2B invoice. The foreign buyer will not be on the KSeF system, so in practice the Polish seller might additionally send a copy (PDF/XML) to the buyer for their records, but the official invoice for Polish VAT purposes is the KSeF file (with 0% VAT or “reverse charge” noted as appropriate). Conversely, if a Polish company acquires goods/services from an EU vendor, the foreign supplier’s invoice is outside KSeF (since the foreign entity isn’t in the system). The Polish buyer will simply receive a normal invoice (e.g. PDF) from the supplier and will self-account for VAT (in the VAT return/SAF-T). Such incoming foreign invoices are not submitted to KSeF by the Polish buyer. Instead, the Polish buyer will mark these in its records for monthly reporting (using special codes in the SAF-T file to indicate an invoice issued outside KSeF). In summary: Polish-issued cross-border invoices go through KSeF; foreign-issued invoices do not (they fall under “e-reporting” via the VAT records, not real-time clearance). [grantthornton.pl] [crido.pl]
Imports and Exports (Extra-EU): Exports from Poland (supplies to customers outside the EU) are handled the same as intra-EU outbound – the Polish exporter must issue the invoice via KSeF (with VAT zero-rated for export). Imports into Poland (goods brought in from outside the EU) typically don’t involve an invoice issued by a Polish entity at all (the seller abroad issues it, and customs documentation is used for VAT). So there is no Polish invoice to put in KSeF for a standard import; the import VAT is handled via customs and the VAT return. If a Polish entity does issue any invoice related to an import (for example, an import agent re-invoicing costs), that would follow normal rules (KSeF if applicable). Generally, pure imports are outside the scope of e-invoicing (they are instead a matter of customs reporting), though they will still appear in the SAF-T/VAT return information for tax purposes (not in real time). [grantthornton.pl]
Cross-border B2B services: If a Polish business provides services to a foreign business (outside Poland), it will issue a KSeF invoice (typically with “VAT Reverse Charge – Article 28b” or similar notation and no VAT). If a Polish business receives services from a foreign provider (where the Polish company must reverse-charge VAT), the invoice from the foreign provider is outside KSeF (similar to intra-EU acquisitions). The Polish company may need to create an internal document for accounting, but there is no requirement to self-issue an e-invoice into KSeF for such purchases – the transaction will be accounted via the VAT return. (Poland did not introduce a separate “real-time report” for cross-border purchases; the existing monthly JPK_VAT report covers it.). [crido.pl]

Does the regime include special transaction scenarios? Yes – the e-invoicing mandate is broad and encompasses self-billing and most complex transaction types, with few exclusions:

Self-billing (buyer-issued invoices): Allowed and in-scope. Poland permits self-billing (e.g. where a buyer issues the invoice on behalf of the supplier, known as “samofakturowanie”), provided both parties agree in advance. Under KSeF, self-billing is supported – the buyer can issue a structured invoice through KSeF and it will be considered a valid invoice for VAT. The seller must authorize the buyer for this; in practice, the seller files a form (ZAW-FA) with tax authorities to grant the buyer permission to issue invoices in KSeF on the seller’s behalf. Once authorized, the buyer (or an appointed agent) issues the invoice via KSeF just like a normal invoice (the schema has fields to indicate it’s a self-billed “VAT RR” invoice, etc.). The invoice will appear in the seller’s KSeF account as soon as it’s issued. All the usual content requirements apply – self-billed invoices must contain the same data as a regular invoice and typically include a notation that it’s issued by the buyer. There are no extra steps (like seller approval in the system) beyond the initial authorization; the KSeF submission itself is the official invoice. In short, self-billing is fully integrated: it must go through KSeF if the transaction is otherwise in scope (no exemption for self-billed invoices). [kpmg.com] [dudkowiak.com] [kpmg.com], [dudkowiak.com]
Triangulation and chain transactions: No special exemption – invoice each leg via KSeF if Polish VAT applies. In a triangulation (A→B→C supply chain) or other multi-party chain, each invoice between parties is treated individually. If a Polish entity is involved at any point issuing an invoice, that invoice must go through KSeF (assuming the Polish issuer is VAT-registered). For example, in an EU triangulation where a Polish company is the intermediary (B), it will receive an invoice from Supplier A (foreign, not in KSeF) and must issue an invoice to Customer C (foreign) – that outgoing Polish invoice to C goes via KSeF (marked as intra-Community supply). The incoming invoice from A, being foreign, stays outside KSeF but will be recorded in the Polish B’s SAF-T with an “outside KSeF” code. Similarly, if a Polish firm is the first or last in a chain, any invoice it issues to the next party in the chain is subject to KSeF clearance. There is no unique “triangulation invoice” format; these are regular invoices (usually zero-rated for intra-EU) processed through KSeF with appropriate VAT flags. Thus, triangulation does not escape the mandate – each domestic issuance is handled normally in KSeF. The same logic applies to domestic chain transactions (e.g. a Polish manufacturer sells to a Polish distributor who sells to a Polish retailer – each sale is B2B domestic, so both invoices go through KSeF). [grantthornton.pl] [crido.pl]
Special VAT regimes (margin schemes, travel agents, etc.): In-scope (with standard invoice content), except OSS/IOSS not in KSeF. The KSeF system is designed to handle standard VAT invoices. Special regimes like the margin scheme or the tour operators’ margin scheme still require invoices to customers, but these invoices usually have no VAT amount (they show a special remark that VAT is accounted within margin). Such invoices can and should be issued in KSeF if the transaction occurs under the mandate (e.g. a Polish travel agency issuing an invoice to a business customer would use KSeF, indicating “margin scheme” in the relevant field or annotation). There is no exclusion for margin scheme invoices – the structured format allows adding notes about the scheme. Similarly, installment payments, down payments (proforma invoices are not actual VAT invoices, but final VAT invoices for advances are in KSeF), and other special cases all fall under the general rule: if an invoice is required by VAT law, it should be electronic via KSeF. The only notable exclusions are for cases explicitly carved out by regulation due to technical limitations: for instance, invoices issued under the EU One-Stop-Shop (OSS) or Import OSS regimes are excluded from KSeF. OSS/IOSS invoices (typically B2C exports or digital services where VAT is reported through OSS) continue to be issued outside KSeF and reported via the OSS portal instead. Another exclusion is for certain documents treated as invoices but with limited data (see Section 7 on exemptions). Aside from those, special VAT schemes like second-hand goods (margin) or travel services have no dedicated exemption – those invoices will be sent through KSeF like any others, with the appropriate VAT designation (e.g. “VAT marża” note). [grantthornton.pl]

2. Taxable Persons in Scope

All taxable persons (VAT taxpayers) who are required to issue invoices under Polish VAT law are within the scope of the e-invoicing mandate, regardless of size or location, with very limited exceptions. In practice:

Established entities (Polish businesses): Covered. Any business established in Poland that is registered for VAT (whether as an active VAT payer or under VAT exemption) falls under KSeF. This spans corporations, SMEs, micro-businesses, sole proprietors, partnerships, etc. All sectors are included – manufacturing, retail, services, etc. – there are no sector carve-outs in the law (e.g. finance or healthcare companies are not exempt simply by industry; if they issue VAT invoices, they must use KSeF). Even entities that are VAT-exempt (e.g. a small business under the PLN 200k/year turnover exemption or one providing only VAT-exempt services) are included if they choose or are required to issue invoices. (Such entities often still issue invoices at customer request or for B2B sales, and from 2026/27 those invoices will be electronic.) The Polish VAT Act was explicitly amended to state that both active VAT-payers and VAT-exempt taxpayers must use the e-invoicing system for any invoices they issue. [poland-accounting.eu]
Non-established entities with a Polish VAT registration: Covered. Foreign businesses that are not established in Poland but have obtained a Polish VAT number (e.g. through registering as a VAT payer for local transactions or for OSS) are in scope. For example, a German company with a Polish VAT registration that sells goods within Poland and issues Polish VAT invoices must use KSeF for those invoices, even if it has no fixed establishment in Poland. Initially, Poland considered making such usage optional, but the latest rules indicate that by 1 April 2026, all VAT-registered businesses, including foreign ones, must comply. Notably, if a foreign entity has a fixed establishment (FE) in Poland, it is definitely obliged to use KSeF for invoices issued from that FE. If a foreign entity is VAT-registered without an FE, it is still expected to use KSeF for any invoices it issues under that Polish VAT number (the KSeF system allows logins via EU VAT identification and has authentication methods for foreign users). The Ministry of Finance has flagged potential interpretation issues about what constitutes an FE, but the safe assumption is that any foreign trader registered for VAT in Poland is subject to the mandate for their Polish invoices. One nuance: foreign entities not registered for Polish VAT at all (no tax presence in PL) are obviously out of scope – they cannot and need not use KSeF. For example, a UK company selling goods to Poland on DDP terms without Polish VAT registration would just issue its normal invoice and that’s outside KSeF (the Polish buyer handles import VAT). [fonoa.com] [poland-accounting.eu] [ec.europa.eu]
Entities without a fixed establishment in Poland: This overlaps with the above – having or not having an FE doesn’t change the obligation if you are VAT registered. The mandate is tied to being a “taxpayer” as defined in Poland. So a foreign company with only a VAT ID (and no physical presence) still must comply. During the voluntary phase, such companies could opt in to KSeF (there was a provision allowing voluntary use for foreign VAT payers without FE). But as we approach mandatory phase, Poland has given these companies until 1 April 2026 to get ready (foreign VAT payers weren’t expected to join by Feb 2026 if they are not “large taxpayers” by Polish definition). By that date, any non-established VAT payer should be issuing via KSeF. Polish guidance has been produced to help foreign companies navigate this (e.g. using qualified electronic seals or having a fiscal representative set up the KSeF access). [grantthornton.pl]
Exemptions and special cases: There is no blanket exemption for any category of taxpayer based on size or sector – only temporary deferrals (see Timeline). Even small and micro businesses are only temporarily excluded until their phase-in date, not permanently exempt. However, the regulations list certain scenarios where an invoice need not be issued via KSeF – these are not tied to the taxpayer’s identity, but to the type of document (see Section 7 for details on those exemptions, like certain transport tickets, etc.). Aside from those specific document-type exclusions, every taxable person who issues an invoice must do so through KSeF once applicable. Taxable persons who were previously not obligated to issue invoices at all (e.g. small retail only giving receipts) don’t suddenly incur an invoice obligation – KSeF doesn’t create new invoicing duties, it only changes the format when an invoice is issued. For example, a small shop that currently only gives fiscal receipts can continue to do so (those receipts are not required to be turned into KSeF invoices unless the law requires an invoice for some reason). Another edge case: unregistered “flat-rate farmers” who sell to businesses – currently the buyer issues a “VAT RR” self-invoice on their behalf. Under KSeF, those VAT RR invoices will be handled by the buyer through KSeF (so that transaction is covered, though the farmer themselves isn’t on KSeF). [poland-accounting.eu], [mddp-outsourcing.pl] [getsix.eu], [getsix.eu] [kpmg.com]
Optional participation models: Poland launched KSeF on a voluntary basis from January 2022. During this phase (2022–2025), any VAT-registered business could opt to issue structured e-invoices through KSeF (and benefit from a faster VAT refund). Participation was low but available. As of now, with mandatory rollout imminent, “optional” use mainly concerns scenarios that are still not required by law: chiefly B2C invoices (a business may choose to channel its consumer invoices via KSeF voluntarily), and foreign VAT-registered businesses until their deadline (some may opt to start earlier). Also, businesses not yet in their mandatory phase (e.g. a small business in early 2026 before April) can voluntarily start using KSeF in advance if they want. There is also an ongoing test environment and pilot programs – e.g. a KSeF 2.0 test portal was made available in late 2025 for companies to practice issuing invoices (with no legal effect). In summary, as of 2026 the system is essentially compulsory for all relevant taxpayers, so “optional participation” only applies in limited senses: issuing B2C invoices via KSeF is optional, and receiving invoices via KSeF was optional prior to Feb 2026 (after which it becomes mandatory to receive – see Timeline). [bdo.global] [atl-law.pl]

3. Implementation Timeline

Poland’s e-invoicing mandate has had a shifting timeline, but it is now finalized. Below is the full timeline of implementation milestones, from legislation to voluntary phase to mandatory phases and grace periods:

Legislative Adoption: Poland obtained EU permission in June 2022 (Council Implementing Decision (EU) 2022/1003) to proceed with a mandatory e-invoice system through end of 2026. The Polish Parliament initially passed an amendment to the VAT Act on 16 June 2023 to introduce KSeF from 1 January 2024 (with mandatory phase starting 1 July 2024). However, due to technical and readiness issues, this was postponed. A further amendment (Act of 9 May 2024) delayed the mandate to 2026. Finally, on 27 August 2025 the President signed the Act of 5 August 2025 into law, definitively setting the mandatory rollout dates in 2026 and 2027. This Act (published in Dz.U. 2025 poz. 1598 – the official Journal of Laws) is the binding legislation confirming the KSeF mandate. In addition, in late 2025 the Ministry of Finance issued four key implementing regulations (signed 7-12 December 2025) that detail how KSeF operates, exemptions, offline mode, etc.. These came into force around the end of 2025 in preparation for go-live. [ec.europa.eu] [grantthornton.pl], [ec.europa.eu] [atl-law.pl], [poland-accounting.eu] [atl-law.pl], [getsix.eu]
Voluntary/Pilot Phase: 1 January 2022 – January 2026. KSeF has been available to taxpayers on a voluntary basis since Jan 2022. During 2022–2023, only a few businesses adopted it (mainly to get the 40-day VAT refund incentive). The system was running in parallel with traditional invoicing. In 2023, about 2.5 million e-invoices were issued via KSeF (vs hundreds of millions of total invoices, highlighting that it was mostly testing). In mid-2025, Poland released an updated KSeF 2.0 API and opened a public test environment for businesses to trial the new schema FA(3). From November 2025, a taxpayer application (KSeF 2.0) test version was made available. Essentially, late 2025 was a pilot testing period using the final specifications. No legal obligation existed during the voluntary period – it was for early adopters and testing. The voluntary phase effectively ends on 31 January 2026, as mandatory use begins the next day for the first group. [bdo.global] [kpmg.com] [atl-law.pl]
Mandatory Go-Live (Phased Rollout): Feb 2026, Apr 2026, Jan 2027. Poland chose a phased implementation by taxpayer size, to ease the transition: [atl-law.pl]
- 1 February 2026 – “Large taxpayers” go live: Companies exceeding PLN 200 million gross turnover in 2024 must comply from this date. This roughly corresponds to large enterprises (by Polish standards, ~EUR 45M turnover). These companies are required to start issuing all their invoices via KSeF from Feb 1, 2026. Important: All businesses, regardless of size, must be ready to receive invoices via KSeF starting 1 Feb 2026, even if they themselves are not yet mandated to issue them. That means smaller companies still in phase-in must have access to KSeF to retrieve invoices from their large suppliers on Day 1. [atl-law.pl], [poland-accounting.eu] [mddp-outsourcing.pl]
- 1 April 2026 – “All other entrepreneurs”: All remaining VAT-registered businesses (medium, small, micro – any that didn’t exceed the PLN 200m threshold) come into scope on April 1, 2026. This includes the vast majority of companies, down to sole proprietors. Notably, this April wave also explicitly covers foreign VAT-registered companies without an FE, as confirmed by the Ministry’s drafts. By this date, essentially every business that issues an invoice in Poland must be using KSeF, except the smallest of the small (see next bullet). [atl-law.pl], [taxnews.ey.com] [taxnews.ey.com]
- 1 January 2027 – “Micro taxpayers” final phase: The mandate is extended to the very smallest invoicing entities – those whose monthly sales invoicing does not exceed PLN 10,000 gross (approx €2,000). These are micro-entrepreneurs who issue only a handful of invoices. They get an extra nine months beyond others, making KSeF obligatory for them from start of 2027. In practice, this category might include some small exempt businesses or individuals occasionally issuing invoices. By Jan 1, 2027, the mandate achieves full coverage of all businesses down to the tiniest. [atl-law.pl]
Rationale: This phased schedule was enacted to give larger companies (with more IT resources) the responsibility to lead, while giving smaller firms additional time to adapt. Taxpayers could determine their phase based on their 2024 sales figures (gross). Note that new companies in 2025 would fall into April 2026 by default (unless they unexpectedly exceed the large threshold). The cut-off of PLN 10k monthly for 2026 effectively carves out businesses that invoice very infrequently or minimally – letting them observe for a year before joining. [poland-accounting.eu] [atl-law.pl]
Grace Period (Enforcement Delay) & Transitional Rules: Feb 2026 – Dec 2026. To further smooth the implementation, Poland instituted a grace period through the end of 2026. During this period:
- No financial penalties will be imposed for not using KSeF correctly. The law defers the application of fines until 1 Jan 2027. (Tax authorities will focus on educating and assisting rather than penalizing in 2026.) [atl-law.pl], [crido.pl]
- Transitional allowances: Some flexibility is given in 2026 for certain cases. For example, from 1 Feb to 31 Mar 2026, businesses that are not yet mandated (the small/medium ones) but voluntarily start using KSeF can still revert to old invoicing if needed without penalty. More concretely, during Feb–Mar 2026, if a non-“large” taxpayer issues an invoice outside KSeF, it’s not an offense (since their mandate starts in April). Similarly, from 1 Apr to 31 Dec 2026, any taxpayer (including those who should be in KSeF) is allowed to issue invoices in paper/electronic form up to a limit – specifically if their total invoiced sales in a month do not exceed PLN 10,000 gross. This means the smallest businesses (those under the monthly threshold) can effectively continue using their old invoicing method through 2026 without penalty, until they hit the threshold or until year-end. It’s essentially a deferred mandate for them (which aligns with the Jan 2027 phase). If they exceed the 10k monthly invoicing in any month, the law says they must switch to KSeF from the invoice that causes exceedance. Also, between Feb–Dec 2026, businesses obliged to use KSeF may continue to issue fiscal cash-register receipts (with NIP) that serve as invoices in certain cases. Poland has a practice where a simplified receipt under 450 PLN with the buyer’s tax number can count as an invoice; the new rules allow that practice to carry on through 2026. After 2026, such receipts with NIP will no longer substitute for an invoice – a full KSeF invoice will be needed. [poland-accounting.eu] [poland-accounting.eu], [taxnews.ey.com] [mddp-outsourcing.pl]
These transitional rules aim to ensure that micro-businesses and point-of-sale situations aren’t forced into abrupt change right in 2026. Operationally, companies under the threshold could stick to existing processes a bit longer, but they must closely monitor their invoicing volume to know when they’d need to switch, and they still must be able to receive KSeF invoices from others during 2026. [mddp-outsourcing.pl]
Key Dates Recap:
- 27 Aug 2025: Law signed confirming mandate (no further delays). [atl-law.pl]
- Nov–Dec 2025: Final implementing regulations issued; KSeF 2.0 test system and certificate issuance open. [atl-law.pl]
- 1 Feb 2026: Mandate begins – KSeF mandatory for large enterprises; all taxpayers must start receiving via KSeF. [mddp-outsourcing.pl]
- 1 Apr 2026: Mandate extends – all other VAT-registered businesses (except micro <10k/month) must issue via KSeF. [atl-law.pl]
- Throughout 2026: Grace period – no fines, some flexibility for small volumes. [atl-law.pl], [taxnews.ey.com]
- 1 Jan 2027: Full mandatory scope – micro businesses join; enforcement (penalties) begins. KSeF is fully in force for all invoices among Polish VAT payers.
Different timelines for sectors or transactions: There are no separate sector-based dates (unlike some countries that stagger by industry). The stagger is solely by size/volume. One slight nuance: Business-to-Government invoices weren’t explicitly given a separate date because public entities have been ready to receive e-invoices since 2019. Businesses could use KSeF for B2G as soon as they were in the mandate (Feb or Apr 2026) – or they could continue using the PEF until they themselves switch to KSeF. After 2026, we expect many will just use KSeF for B2G since it’s easier to have one system. B2C transactions remain voluntary with no planned date to become mandatory – the government has not indicated any intention to force B2C e-invoicing in the near term (likely because consumer receipts are handled by other digitization efforts, like online cash registers, separately). [taxnews.ey.com]

In sum, the timeline was pushed back multiple times but is now fixed: starting Feb 2026 Poland is rolling out mandatory e-invoicing in three waves, giving everyone effectively a year (2026) to adjust under lenient enforcement, with full strict compliance expected in 2027. [atl-law.pl], [atl-law.pl]

4. Technical & Functional Requirements

Poland’s e-invoicing framework is built on a central clearance platform (KSeF) with a specified electronic invoice format and strict validation rules. Key technical/functional aspects include:

E-invoice Format: All invoices must be submitted in a structured XML format conforming to the Polish “FA(3)” schema (the official logical structure for e-invoices). This schema is defined by the Ministry of Finance and is an XML that encapsulates all required invoice data (seller, buyer, line items, tax amounts, etc.) in a machine-readable form. It is not simply an image or PDF – formats like PDF, Word, or scanned invoices are not accepted as invoices in KSeF. The FA(3) schema aligns broadly with the EU e-invoice standard (EN 16931) in terms of data fields, and it has some extensions for Polish-specific content (e.g. distinguishing domestic vs. foreign transactions, or mandatory Polish fiscal annotations). It’s similar in spirit to PEPPOL BIS 3.0 but is a distinct schema tailored to Polish VAT requirements. For example, it includes fields for the Polish legal basis of VAT exemptions, split payment indicator, etc. The schema is published openly – businesses and software providers use it to format their invoice data. In practice, companies will either use software that generates the XML or use the government’s tools to input invoice details which then produce the XML. There is no support for other formats (like UBL or EDIFACT) directly – everything must be converted into the FA(3) XML when sent to KSeF. (PEPPOL can still be used in the B2G context via PEF, but PEF will convert invoices into the required format for KSeF if needed in the future integration.) Also noteworthy: attachments to invoices are allowed in certain cases (from 2026, KSeF supports attachments such as PDF documents in addition to the XML) but the core invoice data must be in the XML itself. The attachment feature is mainly for supplemental info; it requires prior notification to use and the attachment is stored in KSeF linked to the invoice. [dudkowiak.com] [atl-law.pl], [dudkowiak.com] [ec.europa.eu] [poland-accounting.eu], [taxnews.ey.com]
E-reporting Format & Structure: “E-reporting” in the Polish context primarily refers to the ongoing usage of the JPK_VAT (SAF-T) file that businesses submit to tax authorities. Poland has not introduced a separate new report for transaction data outside of the invoices; instead, they’ve integrated KSeF with the existing monthly VAT filings. Starting from settlement period February 2026, the JPK_VAT file (which combines the VAT return and sales/purchase ledger) will include additional fields for KSeF. Specifically, each sales and purchase record in SAF-T will indicate whether the invoice was issued in KSeF and, if so, what its KSeF number is; if not, the record will be marked with one of the new codes (“OFF”, “BFK”, “DI”) to explain why no KSeF number is present. For example, a domestic invoice outside KSeF (maybe issued during an outage) is marked “OFF”, a paper invoice or foreign invoice is “BFK”, etc. These changes effectively constitute the e-reporting side – they ensure that any invoice that wasn’t cleared through KSeF is still reported through the monthly file. There is no real-time reporting form separate from KSeF. KSeF itself transmits the invoice data to the tax authority instantly (so that serves as real-time reporting for those transactions), and for any invoices not in KSeF, the authority relies on the monthly aggregated report. Thus, companies will continue to submit monthly JPK_VAT files, now enhanced with KSeF info. Aside from SAF-T, there are also special summary reports for certain schemes (like OSS quarterly reports, but those are separate from KSeF and unchanged by it). In summary: the e-invoice is the report. Poland’s motto is that KSeF data will “replace traditional VAT reporting” gradually. Indeed, since October 2020, Poland has already abolished a separate VAT return form in favor of the JPK_VAT file. KSeF further automates collection of invoice data, potentially reducing the burden of compiling those monthly reports (though for now the obligation to file SAF-T remains). [atl-law.pl], [crido.pl] [ec.europa.eu], [ec.europa.eu] [fonoa.com]
Validation Rules: The KSeF platform performs automatic validation on each invoice submitted. When a business’s system sends an invoice to KSeF (via API or via the web portal), KSeF will verify the structure and required content. If the invoice XML does not conform to the FA(3) schema or misses mandatory fields, KSeF will reject it and not assign it a KSeF number. Only once it passes validation does it get an official timestamp and unique KSeF ID. Mandatory data elements include all the information normally required by Polish VAT law (per Article 106e of the VAT Act): seller and buyer identification (tax IDs, addresses), invoice date, issue date, line item details, net amounts, VAT rates and amounts (or reason for exemption), gross totals, currency, etc. The schema also requires certain standardized codes, such as document type codes (e.g. FV for regular invoice, KOR for correction invoice) and if applicable, GTU codes (Poland uses codes for certain product groups in SAF-T) – these have been incorporated into KSeF schema or will be derived for SAF-T. The system also validates some content logically (e.g. that arithmetic calculations are correct, that required references are present for credit notes). If an invoice fails validation, it is not considered issued – the issuer must correct the errors and resend. This stringent check ensures high quality of data. KSeF also assigns a unique identification number to each accepted invoice. This KSeF number is important because it must later be cited in VAT records and is proof of clearance. The numbering is centrally generated (businesses don’t assign their own invoice numbers anymore in the legal sense, though they can still use an internal number alongside). Additionally, certain business rules are enforced: for instance, you cannot issue two invoices with the same combination of series/number in a short timespan, you cannot issue an invoice dated before the last one if series logic doesn’t allow it, etc. Some of these are inherently solved by the system’s sequential ID assignment. [bdo.global] [dudkowiak.com]
Mandatory Data Elements: By law and schema, an e-invoice must include all elements that a paper invoice would require, but in structured form. Some fields in the electronic schema correspond to things that used to be free-text on paper. For example, if an invoice is VAT-exempt, the schema has a field to specify the reason/code for exemption (rather than the issuer typing a note). If an invoice is a corrective (credit/debit) invoice, there are fields to reference the original invoice’s number and date and now the original invoice’s KSeF ID as well. Invoices also carry metadata like a transaction type (domestic, intra-EU, export, etc.) which helps route them. Moreover, Poland requires that certain indicators be present: e.g. a flag if split payment is required, or a flag if the invoice is issued in offline mode. These are part of the XML. While businesses don’t manually add a “flag” – their software will based on context – it becomes a mandatory element in those cases (e.g. P_1 field for offline issue date in case of offline mode). Digital signature of the invoice by the issuer is not required for KSeF invoices. Authenticity and integrity are ensured by the system itself (through secure channel and assigning a tamper-proof ID/timestamp). In fact, the Ministry explicitly does not require a qualified e-signature or seal on each invoice file (unlike some other countries). The sender authenticates to KSeF via certificate or token (see Transmission section), and that is deemed sufficient. Thus, fields for signature aren’t part of the content – instead KSeF affixes a time stamp as a sort of digital seal. There are also optional data elements that can be included – for example, an invoice can carry buyer’s order number, payment terms, etc., which while not strictly mandated by tax law, are often used in B2B; the schema provides fields for these so that the XML can serve both compliance and commercial purposes. [atl-law.pl] [bdo.global] [fonoa.com]
Digital Signature / Integrity Requirements: As noted, invoices don’t need to be individually signed by the issuer with an e-signature before sending. Integrity is guaranteed by the KSeF platform. Once an invoice is accepted, it cannot be altered – it’s stored in the government system. The KSeF number and timestamp serve as evidence that the content is fixed at that point. If an invoice needs correction, a separate correction invoice must be issued (also through KSeF) – one cannot simply amend the original. Polish law required that e-invoices (outside KSeF) ensure authenticity and integrity (by signature or EDI controls) historically; with KSeF, that condition is fulfilled by using the system. Additionally, each invoice’s data is available to tax authorities immediately, adding another layer of trust since any tampering would be evident. For external archiving, if businesses keep copies, they should maintain the original XML and metadata to preserve integrity. (If printing or converting for human reading, the original electronic form must be retained to meet integrity rules in case of audit.) [bdo.global]
Real-Time / Near-Real-Time Processing: KSeF is essentially a real-time clearance system. The workflow is: an invoice is issued at the moment it is successfully uploaded to KSeF and validated. In real-time, the system assigns it an ID and time-stamp. For online submissions, this typically occurs within seconds. The buyer can then retrieve the invoice moments after issuance. The Polish VAT Act now defines the “issuance” of an invoice as the moment it’s sent to KSeF (or for offline mode, the timestamp in the invoice when created offline). That means legally, an invoice date is when it goes through clearance. In practice, the system is near-instant for normal operations – effectively real-time. [poland-accounting.eu]
- Deadlines for transmission: In general, there is no grace period of X days for sending an invoice – tax law already requires invoices to be issued promptly (by the 15th of the next month at latest for a given sale, in many cases). Under KSeF, if you’ve made a sale that requires an invoice, you are expected to create and send it via KSeF by that same deadline (which typically means as soon as the transaction occurs or shortly after). Because KSeF is available 24/7, there’s no reason to delay issuance. The only scenario where a delay is allowed is the contingency (offline) mode: if KSeF is down or the taxpayer has no connectivity, they may issue the invoice in “offline24” mode and then must transmit it to KSeF once the issue is resolved. The regulations specify the deadline: an offline invoice should be uploaded by the next business day after connectivity is restored (and in any case within 7 days). During such a delay, the invoice carries a special offline marker and QR code to ensure it can be verified once in KSeF. Other than that, no routine T+1 or T+N delay is built into the system – it is meant to be essentially immediate. Poland did consider allowing a general “next day submission” for all invoices (some earlier drafts mentioned possibly T+1 for everyone), but in the final rules this became specifically the “offline mode” concept for exceptional cases. Therefore, operationally, businesses will be issuing invoices in real-time. [bdo.global] [bdo.global], [poland-accounting.eu]
- Periodic / summary reporting: There is no requirement to send a monthly summary of invoices to the tax authority, since KSeF provides them all individually and the SAF-T file covers the totals. So unlike some systems (e.g., Spain’s SII requires a summary if not immediate), Poland does not ask for any separate summary report – just the regular JPK_VAT and the invoices themselves. One exception: if a taxpayer is not yet in KSeF (e.g. in Jan 2026 a small taxpayer not mandated until April), they simply continue their normal monthly SAF-T which serves as the report of their invoices issued outside KSeF for that period.

In short, Poland’s technical solution is a centralized, API-driven platform using a standardized XML invoice. Invoices are sent and validated in real-time, ensuring each contains all required info and is digitally stamped by the tax authority. The system blends continuous transaction reporting (each invoice to the tax authority immediately) with periodic summary reporting (monthly SAF-T) for completeness. Businesses must adapt their IT to produce the required XML and handle responses from KSeF (e.g. success or error messages), and ensure they have procedures for any downtime (offline mode). The government has provided extensive documentation (schemas, API specs, and even free applications) to facilitate this transition. [bdo.global] [ksef.podatki.gov.pl]

5. Transmission & Workflow

How invoices are transmitted to the tax authorities (and to trading partners) under KSeF:

Central Clearance Platform (KSeF): KSeF is a single, centralized government platform. All e-invoices are sent to this platform either via an API integration or via government-provided web/mobile applications. Unlike some countries with multiple clearance nodes or certified service providers, Poland’s model is one central portal operated by the Ministry of Finance. So, the workflow is: the supplier (or self-biller) transmits the invoice data to KSeF → the KSeF system validates and “clears” it (assigns an official number and timestamp) → the buyer can then retrieve the cleared invoice from KSeF. By law, delivering the invoice to KSeF counts as delivery to the buyer – in other words, once it’s in KSeF, the invoice is considered issued and received by the counterparty, even if the buyer hasn’t yet downloaded it. [dudkowiak.com] [mddp-outsourcing.pl]
Interoperability Model: Because KSeF is centralized, the concept of interoperability is mostly internal – i.e., integrating different company systems with KSeF. Poland is not at this stage using a network-of-networks approach for B2B. Instead, every invoice flows through the one government system (a clearance model). However, KSeF will integrate with the existing B2G e-invoicing platform (PEF) to ensure a unified approach by 2026. PEF (Platforma Elektronicznego Fakturowania) was Poland’s PEPPOL-based gateway for public procurement invoices. The plan is for KSeF and PEF to work together so that a company can send an invoice to KSeF and the government entity can receive it either via KSeF or through the PEF/PEPPOL channel linked to KSeF. For typical B2B, interoperability means that any software (ERP, accounting system, invoicing app) can connect to KSeF using the open API – software providers have adapted their systems to output the correct format and call the API. Some providers may act as intermediaries by offering KSeF integration as a service (for example, converting legacy invoice formats to KSeF XML and transmitting), but these are not “platforms” that replace KSeF – they are helpers. Accredited service providers: Poland has not designated specific providers as mandatory conduits. Companies are free to use any third-party solutions or in-house software as long as it communicates with KSeF properly. There is no accreditation requirement, though software must follow the API specs and ensure security. Essentially, the transmission options are either direct (company’s system to KSeF) or via a provider’s system to KSeF – in all cases, KSeF is the endpoint for clearance. [ec.europa.eu], [ec.europa.eu]
PEPPOL or other networks: In the B2B mandate, Poland is not requiring use of PEPPOL. The KSeF API is a bespoke interface (SOAP/REST) to the government portal. That said, there are discussions about enabling PEPPOL connectivity – indeed, the KSeF system could accept invoices from the PEPPOL network if configured, and the official materials mention connecting a “Peppol access point” by granting permissions (there is an option to authorize a PEPPOL service provider to send invoices to KSeF on your behalf). This suggests that if a business uses PEPPOL format and a service, that service can push invoices into KSeF. But at launch, PEPPOL BIS 3.0 is not the native format for KSeF (it must be converted to FA(3) XML). So while PEPPOL is used for B2G historically, B2B will primarily be direct to KSeF. Many companies with international invoicing might use their PEPPOL AP which then interfaces with KSeF, but that’s an optional interoperability solution, not a mandated one. [ksef.podatki.gov.pl] [fonoa.com]
Transmission Channels: The primary channel is the KSeF API (Application Programming Interface). Businesses (or their providers) use web service calls to send invoice files and receive responses. To use the API, one must authenticate – either with a digital certificate issued by the Ministry (KSeF certificate), a Polish e-ID (for individuals), a qualified electronic seal (for organizations), or a one-time token model. Many larger firms will integrate the API into their ERPs for seamless automated invoicing. For smaller entities, the Ministry offers front-end tools: a web portal (app.ksef.mf.gov.pl) where one can manually input or upload invoices, and a mobile app and desktop “e-Mikrofirma” app for basic invoice issuance. These tools in effect act as a GUI on top of the same API. There is no sending of invoices via email or other legacy means to the tax authority – it must be through the portal or API. [dudkowiak.com], [dudkowiak.com] [dudkowiak.com], [ksef.podatki.gov.pl]
Workflow for Buyers: Buyers will typically be notified inside their accounting systems when a new invoice is available (if integrated), or they may have to periodically check the KSeF interface. KSeF itself does not push notifications (e.g. no email is sent to the buyer when an invoice arrives). It’s up to the buyer’s software or process to pull invoices. Many companies will set up an automated fetch of any new invoices addressed to them, using their own KSeF credentials. The government’s KSeF web portal also allows buyers to search and download invoices. So the workflow is symmetrical: the seller sends to KSeF, the buyer retrieves from KSeF. They do not exchange the invoice directly (though nothing stops a courtesy copy being emailed, but that copy has no fiscal value unless it matches the KSeF record). [mddp-outsourcing.pl]
Deadlines for transmission & retrieval: A supplier must transmit an invoice essentially immediately upon issuance (see Section 4: “issue date = submit date”). If they use offline mode due to an outage, the deadline is next working day to upload. For normal operations, there isn’t a grace period like “within 24 hours” – it’s expected to be at the time of sale or shortly after. As for buyers, there is no legal deadline by which they must download invoices from KSeF; however, since the invoice is deemed delivered once in KSeF, the clock for e.g. VAT deduction is running. In practice, a buyer will likely retrieve invoices at least before filing their VAT return for that period, to ensure they have all input invoices. Many will do it daily or weekly automatically. [bdo.global]
Monthly summaries or periodic reporting: As mentioned, there’s no separate monthly invoice listing to send to the tax authority – KSeF eliminates the need to send a sales listing (the authority already has sales invoices from KSeF). For purchases, the SAF-T file each month still serves to report any purchases (including those from abroad or any not in KSeF).
Handling of errors and rejections: If KSeF rejects an invoice upon submission (due to validation error), the invoice is considered not issued. The supplier must fix the data and resend. The platform returns an error code immediately in such cases. If KSeF accepts the invoice, it returns the KSeF number and a confirmation (UPO – official acknowledgment). That UPO can be downloaded as proof. The UPO includes the KSeF ID and a checksum of the invoice data. [ksef.podatki.gov.pl]
Offline (Contingency) Workflow: The “offline24” mode is a special procedure for when a taxpayer cannot reach KSeF (e.g., internet outage or KSeF system downtime). In offline mode, the seller can generate the invoice XML with a special flag and a QR code. The QR code encodes key information including a hash of the invoice data. The seller can give that invoice to the buyer (e.g. as a PDF printout containing the QR or as the XML itself) even though it’s not yet in KSeF. The law allows this to be considered a valid invoice temporarily. Once connectivity is restored, the seller must send those offline invoices to KSeF. KSeF will verify the QR code and data; if it matches and is within the allowed time window, it will accept and assign a KSeF number (the date of issuance in this case is back-dated to what’s on the invoice). If the seller fails to upload in time, the invoice may be considered not reported which can trigger penalties (after grace period). The “offline24” name implies that generally one shouldn’t stay offline for more than 24 hours (indeed the next business day rule). The system also provides an “emergency mode” if KSeF itself is down nationwide – Finance Ministry will announce if KSeF is unavailable; during such time, everyone operates in offline mode and then uploads later, with no penalty as long as done on time. [bdo.global] [poland-accounting.eu]
Receiving workflow (summary): All taxpayers must be able to receive e-invoices from KSeF as of Feb 2026. This means even if you don’t have to issue until April, you need to get your KSeF access sorted by Feb to retrieve purchase invoices from large suppliers. Many small businesses will use the KSeF web portal or mobile app to check for new invoices. Others might grant their accountant or accounting software provider access (via the ZAW-FA authorization mechanism) so that those parties can retrieve invoices on their behalf. KSeF allows delegation: e.g., a business owner can authorize an employee or an accounting firm to access all invoices, without sharing the owner’s personal login. This is done through the Certificates and Authorisations Module (MCU) introduced in November 2025. Once set up, the actual retrieval is straightforward. There is even a feature to search invoices by various criteria, including by buyer’s VAT number or by date range. [mddp-outsourcing.pl] [dudkowiak.com] [ksef.podatki.gov.pl]
Security and Authentication: Each user of KSeF must authenticate. Businesses (other than sole proprietors) typically will use a KSeF issued certificate or a Qualified Electronic Seal to authenticate machine-to-machine. Individuals (like sole traders or representatives) can use Trusted Profile (Profil Zaufany) or a qualified e-signature, etc.. There is also a one-time token method that was allowed (for automated systems) at least until end of 2026, and new e-ID methods (Polish eID node) coming in 2026. All transmissions are encrypted TLS connections. Essentially, one must prove their identity and authorization every time an invoice is sent or retrieved. This prevents unauthorized access to invoice data. Businesses will need to manage these credentials (e.g., obtaining the KSeF certificate starting Nov 2025 was possible so they can install it in their IT systems). [dudkowiak.com] [poland-accounting.eu]

In summary, the workflow is a centralized clearance: suppliers upload to KSeF (via API or portal), the tax authority’s system validates and stores the invoice, and buyers download from KSeF. The timing is real-time except in defined outages. KSeF acts as the intermediary for all invoice exchange – effectively replacing email/post for sending invoices between companies. All data flows through the government’s server, giving the tax authority immediate visibility of transactions and ensuring both parties have a single source of truth for the invoice. The design is meant to be robust (with offline fallback) and accessible (free tools for those without their own IT integration). Deadlines like “T+1 day” apply only to offline uploads; otherwise issuance is on invoice date. And the monthly VAT file ensures any straggling data (like foreign invoices) is captured. [atl-law.pl]

6. Self-Billing

Poland’s e-invoicing framework accommodates self-billing scenarios. Self-billing (where the invoice is issued by the buyer rather than the seller) is permitted under Polish VAT law with the seller’s agreement, and this continues under KSeF with specific procedures:

Allowance under KSeF: Self-billed invoices must be channeled through KSeF just like seller-issued invoices if they pertain to transactions within the mandate. The KSeF system has been designed to handle these cases – indeed, the official KSeF documentation explicitly covers “self-invoicing” and the special case of “VAT RR” invoices. (VAT RR invoices are used when purchasing from certain farmers under a simplification – a classic self-billing case in Polish VAT.) So, yes, self-billing is allowed and those invoices must go through the platform. [kpmg.com]
Procedure and Buyer Authorization: The key requirement for self-billing is the seller’s authorization. Traditionally, the buyer and seller sign a self-billing agreement. Under KSeF, the seller also needs to grant the buyer permission in the KSeF system to issue invoices on the seller’s behalf. This is done via the ZAW-FA notification – a electronic form where the seller (or an authorized person for the seller) logs into KSeF and authorizes a specific entity (the buyer, identified by tax number) to issue invoices in KSeF in the seller’s name. Once this is in place, the buyer can send invoices to KSeF tagging them as issued for that seller. Essentially, KSeF will accept an invoice where the “issuer” field is the buyer only if the proper authorization has been recorded; otherwise, an attempt would be rejected as unauthorized. [dudkowiak.com]
Content and Format: A self-billed invoice in KSeF looks much like a regular invoice, except that the system knows the issuer is actually the buyer. The invoice will still nominally have the seller’s details as the supplier party and the buyer’s details as the customer, because legally it is an invoice of the supplier (just created by the buyer). The invoice should include a notation that it is issued by the buyer (under EU VAT rules, self-billed invoices should mention “self-billing” on them). KSeF likely has a field or will use the issuer identity to implicitly mark it. For instance, VAT RR invoices have specific fields in the schema for the farmer’s data and buyer’s data, and KSeF identifies them accordingly. Aside from that, all mandatory elements (date, description, amount, etc.) are included as usual. The buyer is responsible for the accuracy of those details. [kpmg.com]
Transmission through platform: The buyer (or its agent) will transmit the invoice via API or portal, authenticating with its own credentials but indicating the invoice is being issued under the seller’s account (because of the prior authorization). Technically, the KSeF API allows specifying on whose behalf the invoice is being issued – the buyer would use the authorization token for that seller. Once submitted, the invoice gets a KSeF number and is delivered to both the seller’s and buyer’s KSeF inboxes. The seller will see that invoice in KSeF as if they had issued it (with an indicator it was self-billed perhaps). The buyer will also see it listed as an invoice they issued on behalf of supplier X. Both parties can retrieve it. There is no additional approval step required within KSeF; the seller doesn’t have to “accept” the invoice in the system. The initial agreement (ZAW-FA) is considered the acceptance that the buyer’s invoices are valid. Of course, outside the system, the seller and buyer will have arrangements to handle any discrepancies, but from a KSeF perspective the invoice is fully valid once it’s in.
Buyer-side validation or approval: Since the buyer is the one creating the invoice, the concept of “buyer approval” is inverted – actually the seller has ceded control. The tax authority doesn’t impose any further approval workflow beyond requiring that initial consent. So, KSeF does not, for example, send a notification to the seller to approve each self-billed invoice. It is assumed that the arrangement is in place and any disputes would be handled between the parties. If a seller disagrees with a self-billed invoice, they might have to issue a correcting document (or ask the buyer to do so), but through KSeF as well. Importantly, the buyer in a self-billing scenario needs to ensure they have the seller’s correct details and follow any conditions of their agreement (like numbering conventions). Invoices issued by buyers will carry the series/number that the buyer assigns, but KSeF’s unique number will ultimately identify it.
Mandatory content rules: Polish VAT regulations for self-billing (VAT RR invoices, etc.) require specific information – for example, VAT RR (farmer purchase) invoices require the phrase “Faktura VAT RR” and certain declarations from the buyer. The KSeF schema has dedicated structure for VAT RR to include all those mandatory pieces. For other self-billing cases, the invoice must include the usual elements and likely a note such as “samofakturowanie” (self-billing) as per EU recommended practice. KSeF didn’t explicitly list that note requirement in schema (since it’s more of a textual thing), but presumably those who self-bill will include it in the invoice text fields. Additionally, the self-billed invoices are subject to the same validation rules – if something required is missing, it will be rejected. [kpmg.com]
Restrictions or notifications: Other than needing the seller’s authorization, there aren’t extra restrictions. The system prevents unauthorized self-billing by requiring ZAW-FA; beyond that, one buyer could potentially self-bill multiple sellers and one seller could authorize multiple buyers. Each relationship requires separate authorization form submissions. The seller can revoke authorization at any time (which they would do via KSeF as well). If revoked, subsequent invoices from that buyer on seller’s behalf would be refused by KSeF. The system keeps track of these permissions centrally. Poland does not require a separate notification to the tax office outside KSeF for self-billing – the act of using KSeF with the proper roles covers that notification (historically, no explicit notification was needed either, just an agreement). [dudkowiak.com]

In summary, self-billing is fully supported: the buyer issues the invoice through KSeF after obtaining the seller’s go-ahead (via a formal authorization in the system). The invoice flows through KSeF and is delivered to both parties just like any other invoice. Both seller and buyer can then account for the VAT (buyer claims input, seller declares output) using that KSeF record. The system ensures control by requiring upfront authorization, but once that’s done, it treats the buyer-submitted invoice as if the seller issued it. There are no special extra compliance steps beyond what already exists for self-billing (like having an agreement and marking the invoice accordingly). [dudkowiak.com] [kpmg.com]

7. Triangulation & Special Scenarios

Poland’s e-invoicing regime handles complex VAT scenarios (triangulation, chain transactions, reverse charges, exemptions, etc.) largely within the standard framework of KSeF, with some clarifications:

Triangulation (EU three-party transactions): In an EU triangulation, typically three businesses in three member states are involved in a supply chain for goods, applying a simplification where the intermediate supplier doesn’t register in the destination country. For KSeF’s purposes, what matters is whether a Polish entity is issuing an invoice. If a Polish company is Party A (first supplier) shipping to Party C in another country, it will invoice Party B (the intermediate buyer) – that is an intra-Community supply from Poland to another EU VAT taxpayer. That invoice must be issued via KSeF like any other export invoice, indicating 0% VAT (with reference to the triangulation simplification in the invoice notes if applicable). If a Polish company is Party B (intermediary) in a triangulation, then it will receive an invoice from Party A (foreign supplier) – which is outside KSeF as it’s issued by a foreign entity – and it will issue an invoice to Party C (foreign customer). The invoice from the Polish intermediary to Party C is again an intra-Community supply (since goods move from A to C across borders) – that invoice must be issued through KSeF as well. The Polish intermediary would mark it with VAT “NP” (not subject in Poland) or 0% as appropriate, and likely mention it’s a “triangulation – Article 135 Directive” scenario. KSeF doesn’t have a special “triangulation document” type, but Polish VAT law requires the invoice to mention “VAT: 0%, triangular transaction” on such invoices, which can be included in the structured data (there are fields for transaction type that likely cover this). If a Polish company is Party C (final buyer) in a triangulation and Party B is foreign, then the Polish company will be receiving an invoice from abroad (likely stating “reverse charge – triangulation”). That invoice is not on KSeF (because the issuer is foreign). The Polish company just accounts for acquisition VAT in its return. In summary, every invoice that a Polish company issues in a triangulation flow goes through KSeF; invoices a Polish company receives from abroad do not (they are handled via VAT return reporting). There is no need for any additional reporting beyond that. The triangulation simplification (where Party B doesn’t vat-register in C’s country) doesn’t change KSeF obligations for Party A or B if they’re Polish – KSeF treats those invoices as just cross-border 0% supplies. [grantthornton.pl]
Chain Transactions (multiple intermediaries or domestic chains): If the chain is entirely domestic (multiple Polish intermediaries buying and selling the same goods before final buyer), then each transaction is just a normal domestic sale – so each invoice between Polish parties must be via KSeF. If the chain extends abroad (more than one foreign party), then the analysis is similar to triangulation: any leg where a Polish VAT-registered entity is the issuer, that invoice is in KSeF; any leg where a foreign entity is the issuer, that invoice is not in KSeF. KSeF doesn’t require linking invoices in a chain (though invoices themselves may reference order numbers etc., which can be included in structured data). The tax law might require notes on certain chain transactions (like call-off stock or consignment stock arrangements), and those notes can be included in invoice content. There’s no special “chain transaction form” – it’s just multiple invoices, each handled separately in KSeF if Polish-issued.
Cross-border Reverse Charge Scenarios: This refers to situations like services supplied by a foreign company to a Polish business (where Polish business must self-account for VAT) or certain goods where VAT is reverse-charged to the buyer. In such cases: if the invoice is issued by a foreign supplier to a Polish buyer (e.g. consulting services from Germany to Poland, or a foreign contractor providing construction in Poland but using reverse charge), the foreign supplier’s invoice will be outside KSeF (foreign entity cannot access KSeF). The Polish buyer will report the transaction in their VAT return (as output and input VAT via reverse charge). There is no requirement for the Polish buyer to generate a KSeF invoice for it. (Poland did not implement a requirement like Italy’s “self-invoice for imports” in KSeF – they rely on the SAF-T declaration to capture these, using the “BFK” or “DI” codes for purchase records without KSeF number.) If a Polish buyer chooses, they might issue themselves an internal document for clarity, but it’s not a fiscal invoice that goes to KSeF; it stays in their records. On the other hand, if a Polish company is providing a service and the reverse charge applies within Poland (some domestic sales like scrap metal, certain electronics, or construction between VAT payers were reverse-charged under old rules – though many of those moved to split payment now), those are still domestic invoices between two Polish VAT payers. They must be issued via KSeF as well, with the invoice indicating “reverse charge” (NP, not charged VAT). So for domestic reverse charge, KSeF handles it – the schema has a field to mark the sale as reverse-charged. If a Polish company sells to an EU business and the service is taxed by reverse charge in the client’s country (general B2B rule), that’s just an out-of-scope export of service – the Polish company issues the invoice via KSeF with no VAT (and possibly phrase “reverse charge to recipient”). If a Polish company buys services from outside EU (import of service), by law they often have to issue an internal document for VAT books. However, Poland did not clarify that such internal documents need to go into KSeF – given the new SAF-T codes, it seems they intend those to be just marked as DI (document other than invoice) in the VAT records. So, no, KSeF does not require creating self-invoices for cross-border purchases – the SAF-T will reflect them. [crido.pl] [atl-law.pl]
Zero-rated Supplies (Exempt with credit, like exports, intra-EU): These are very much in scope. A zero-rated invoice (0% VAT) is still a VAT invoice and must be issued through KSeF if by a Polish supplier. KSeF has fields for VAT rate and amount – putting 0% is completely allowed. It also likely requires an indication of the reason (e.g. “export of goods – Article 41(6) VAT Act” or “intra-Community supply – Art. 138 Directive”). Typically, invoices for intra-EU supplies need the buyer’s EU VAT ID and a statement that 0% is applied. All that info can be structured or at least included in text. KSeF will not block an invoice with 0% (it’s valid as long as the country codes of buyer vs seller make sense, etc.). Similarly, VAT-exempt supplies (like financial services, medical services if an invoice is issued) are handled by KSeF as well. The invoice would have no VAT amount and would cite the exemption provision. The FA(3) schema has a place to indicate “ZW” (zwolniony – exempt) as the VAT rate, and to specify the legal basis for exemption (like a code for the article of the VAT Act) – this was part of the JPK requirement and is incorporated into e-invoices. [grantthornton.pl]
Exempt Supplies and Special VAT Schemes: Some supplies are exempt from VAT or under special margin schemes (where VAT is not indicated on the invoice). Poland’s regulations did allow that certain fully VAT-exempt businesses could delay using KSeF until 2027 (that was the case for those only performing exempt activities as cited in the earlier timeline). But ultimately, by 2027 even they must use KSeF if they issue invoices. The margin scheme (second-hand goods, travel): These invoices typically cannot show VAT; they must include a phrase like “margin scheme – second-hand goods/VAT marża”. Under KSeF, such an invoice is still issued, with 0% or no VAT listed and that phrase in a note field (since there’s no VAT to report, it’s effectively treated like an exempt invoice in terms of structure). There’s no indication that margin scheme invoices are exempt from KSeF – they are not in the exemption list of the Dec 2025 regulation. So those must go through KSeF. Travel agents’ margin scheme (VAT on margin for travel services) similarly – invoice issued to customer typically says “VAT margin scheme for travel – no VAT to deduct”. That invoice would be through KSeF if issued by a Polish agency, with the appropriate explanatory text. The buyer (if business) knows they can’t deduct VAT since none shown. [grantthornton.pl] [getsix.eu], [getsix.eu]
Special local nuances / exemptions: The Ministry of Finance issued a regulation listing cases where a structured invoice is not required (i.e. you don’t have to issue via KSeF). These are essentially scenarios where the legal document serving as an invoice has a limited data scope that doesn’t fit the normal invoice schema. Confirmed examples in that list: [getsix.eu]
- Toll motorway tickets/receipts – highway toll receipts with a tax ID (which function as invoices) do not have to be issued in KSeF. [getsix.eu]
- Passenger transport tickets (e.g. train or bus tickets that serve as invoices under VAT rules) are exempt from KSeF. These typically only list fare, VAT and serve as simplified invoices – they remain paper or electronic tickets. [getsix.eu]
- Air transport invoices issued by Eurocontrol (air traffic charges) – these are specialized invoices (often issued by a centralized agency) and are exempt from KSeF. [getsix.eu]
- Receipts with NIP up to 450 PLN (which are treated as simplified invoices) – the regulation implies these can continue to be used and are not required to be reissued in KSeF until end of 2026. In fact, one key change is that after 2026, receipts with buyer’s NIP will no longer count as invoices (to push everyone to KSeF). But during 2026, they are still allowed outside KSeF. So a company making a sale under 450 PLN to a business can still just give a cash register receipt with NIP as invoice through 2026, and that is acceptable (not a violation of KSeF mandate). From 2027, presumably those scenarios should use KSeF or a full invoice. [taxnews.ey.com]
- Certain fiscal documents in specific industries: e.g. bank statements for certain fees or insurance policy documents are often not full invoices. The regulation covers “documents issued in specific cases allowed by the Minister’s regulation” – for instance, some financial services or universal postal services have special invoicing rules. These remain outside KSeF if they fall under that scope (the regulation mentions “cases provided by the Ministry’s regulation”, which includes things like a one-off ticket can be an invoice, etc.). [grantthornton.pl], [getsix.eu]
These exemptions are narrowly defined and mostly concern B2C or mass transactions where an “invoice” as such isn’t traditionally issued. For typical B2B triangular or chain scenarios, no exemption applies – those require invoices which must be in KSeF. Only if a transaction can be legally documented without a VAT invoice (like a ticket or a simplified receipt) can it bypass KSeF.
Domestic special schemes (split payment, bad debt, etc.): Not exactly asked, but worth noting: Poland’s split payment mechanism (mechanizm podzielonej płatności) which is mandatory for some sectors requires an invoice note “mechanizm podzielonej płatności”. KSeF invoices will include that note (there’s a field/flag for “split payment required”). KSeF was initially going to require companies to put the KSeF ID on the bank transfer reference for split payment; this requirement was postponed to late 2026. Credit notes / corrections: these are handled by issuing a correction invoice in KSeF referring the original KSeF number. Debit notes for certain adjustments are replaced by structured correction invoices as well. No more corrective notes by buyers (a practice in PL where buyer could issue a correction note for minor errors) – under KSeF, those will presumably become just correction invoices issued by the original issuer (the Dec 2025 regulation modified rules on corrective documents accordingly). [bdo.global], [taxnews.ey.com]

In essence, triangular and chain transactions do not get a special reporting mechanism – each invoice is handled individually in or out of KSeF depending on who issues it. Reverse charge and exempt transactions are reported through the same system, usually with 0% or “NP” VAT on the invoice. And Poland’s regulations carve out only very specific invoice types (mainly certain tickets, tolls, and OSS transactions) from the e-invoicing obligation. Apart from those, businesses should assume that if they would normally issue an invoice on paper for something, they now must issue it via KSeF. [grantthornton.pl], [getsix.eu]

8. Archiving & Retention

Under the KSeF system, the approach to archiving and retention of invoices changes significantly, because the invoices are centrally stored by the government. Key points on archiving and retention:

Central Storage by Tax Authority: One major benefit of KSeF is that the Ministry of Finance will store all e-invoices in the central system for the legally required period. In fact, the Polish authorities have stated that taxpayers do not have an obligation to archive KSeF invoices themselves – since those invoices reside in KSeF’s database which the tax administration maintains. Invoices in KSeF are available to both issuer and recipient online, and to tax officials. This effectively shifts the burden of maintaining original invoice records to the tax authority (at least for those invoices that are in KSeF). The KSeF platform acts as a secure repository or digital archive for all structured invoices. Taxpayers can retrieve past invoices from KSeF on demand. There is no need to store a separate signed file or paper copy for legal compliance, as long as the invoice is in KSeF. No manual archiving obligation for KSeF invoices was a selling point of the system. [atl-law.pl]
Retention Period: Polish tax law generally requires keeping VAT records (including invoices) for 5 years counting from the end of the year in which the tax became due (effectively up to 6 years in practice, aligning with the statute of limitations). However, there are some references suggesting a 10-year retention for certain records (10 years is often used in EU for invoice storage to align with civil law or for intra-EU transactions). The Fonoa compliance guide indicates a 10-year archiving period in Poland. It’s likely that Poland expects e-invoices to be kept for the same period as accounting records – which, under accounting regulations, is 5 years, but under certain conditions (like EU fund projects or cross-border transactions) could be extended. To be safe, many companies in Poland keep invoices 10 years anyway. KSeF itself is expected to store e-invoices for at least 10 years. Indeed, since Poland’s EU derogation for mandatory e-invoicing runs until end of 2026 (with likely extensions to be sought), the system is intended to be permanent, and the data will likely be retained for a long period. So from the taxpayer’s perspective, those invoices will be accessible in KSeF for at least the statutory period (5 years) and likely longer (10 years has been mentioned as the archiving period in documentation). After the retention period, the law hasn’t stated if KSeF will purge data, but presumably it might eventually, or at least archive them in deep storage. [fonoa.com]
Local vs. EU vs. Third-Country Storage: For invoices not in KSeF (or if a taxpayer wants their own copy), Polish law historically allowed electronic archiving abroad with conditions. Those rules still apply to any records a taxpayer chooses to keep outside KSeF. If a taxpayer stores electronic invoices on their own server or cloud, they must ensure the storage is within the EU, or if it’s in a third country, that it’s accessible from Poland and that tax authorities can get access on request. Typically, companies must notify the tax office if books are kept outside Poland. With KSeF, this becomes less critical, since the official invoices are with the authority anyway. But for completeness: Polish regulations (as per the VAT Act and Ordinance on storage) say invoices can be stored abroad provided online access from Poland is guaranteed for audit purposes and, if outside the EU, usually prior notification is required. Many companies use cloud services (some in EU, some outside); they need to ensure compliance with these conditions. The Fonoa guide notes “Allowed with conditions” for archiving abroad – meaning yes, you can use an EU or non-EU data center if you ensure tax authorities’ access. In practice, since KSeF covers the official archive, companies might just rely on KSeF for compliance and not worry about where their backup copies are stored. But conservative approach: if you do keep backups on e.g. US servers, be prepared to provide them on request quickly in Poland. [fonoa.com]
Integrity, Authenticity, Readability: These requirements for electronic archiving are legally mandated. An invoice must remain authentic in origin, intact in content, and legible throughout the retention period. Under KSeF, authenticity and integrity are inherently ensured: the invoice in KSeF is the original record, timestamped by the tax authority, and cannot be altered without creating a formal correction record. So as long as the invoice is viewed via KSeF, its integrity is guaranteed by the system (no one can tamper with the central database without it being evident). If a taxpayer exports invoices from KSeF (e.g. to store locally), they should make sure those copies remain unaltered (for instance, not editing the XML). KSeF provides an official UPO (receipt) with a hash that can be used to verify that an XML hasn’t changed. For authenticity – traditionally one would require a digital signature or EDI controls; here the fact it’s delivered through KSeF and comes with a KSeF ID is considered sufficient evidence of authenticity. So KSeF fulfills the integrity/authenticity requirement for archiving. Readability: Taxpayers and auditors must be able to read the content of invoices in human-readable form. The KSeF portal can display an invoice in a readable layout (the government has a standard visualization). If invoices are stored outside KSeF, the business must ensure they can render the XML in a legible format (either by using a tool or converting to PDF for reading). Typically, audit rules require that on request, invoices be provided in a readable format (e.g. printouts or PDF) along with the original file. [bdo.global] [ksef.podatki.gov.pl]
Audit Access: Since KSeF is run by the tax authority, auditors (tax inspectors) have direct access to the invoices in the system. This is a crucial change – in an audit, a business will likely not need to send piles of invoices; the auditor can pull whatever invoices they need from the KSeF database. The law explicitly allows tax office to use KSeF data for checks. For invoices outside KSeF (e.g. a January 2026 invoice from a foreign supplier, or an OSS invoice), the taxpayer’s obligation to provide them on request remains. Those will be in the SAF-T records, and an auditor might ask for the physical PDF or document to verify details. Taxpayers should thus still organize any non-KSeF invoices (like import documents, etc.) in an archive. But the bulk of invoices (once KSeF is fully in force) will be accessible to auditors without needing to ask the taxpayer. Companies still may want to keep backups for their own reference or as a precaution, but legally the storage in KSeF suffices. [atl-law.pl]
Archiving Format: If a taxpayer chooses to archive a copy of invoices, the recommended practice is to keep the original XML files (and UPO acknowledgments). Some may also store a human-friendly PDF rendition for convenience, but the original XML is the legal file. The Ministry’s info indicates taxpayers don’t have to store invoices in their own archives at all anymore, but many will for internal control. Those who do must ensure the electronic archive is secure (no modifications allowed to files) and properly backed up. An archive should be indexed (by date/number) to allow retrieval if needed. But again, KSeF is effectively a state-managed archive. One can think of it like this: previously you had to keep paper or electronic invoices for years; now if an invoice is in KSeF, the state keeps the “original” and you are keeping at best a copy. The regulation that “the obligation to archive is removed” for KSeF was highlighted as a major relief for companies. [atl-law.pl]
Third-country storage specifics: If a company does store its own copies on a server outside the EU, Polish regulations (per VAT Act Art. 112a) say the company must ensure the invoices are immediately accessible from Poland. In practice that means a computer in Poland can retrieve and display them without undue delay. Many companies interpret this as keeping an online connection or a mirror in the EU. It’s wise to notify the tax office in writing if large volumes are stored abroad (though when KSeF holds them, this might be moot).
Durability and Format over time: The invoices must remain legible even as technology changes. XML is a durable format (text-based). Tools to view it will presumably be around or can be recreated in the future. The government’s information sheet (the one on logical structure) is provided to help ensure anyone can interpret the data fields. For extremely old invoices beyond a decade, if the system changes (say a new schema), presumably the government will either migrate old data or keep a legacy viewer. Taxpayers should download any needed older invoices before they disappear (though nothing official says they will disappear at year 10, it’s good practice just in case). [ksef.podatki.gov.pl]
Audit Trail: KSeF provides an audit trail of when the invoice was issued, and if any corrections were issued. For archiving integrity, one doesn’t need to maintain a separate audit log since the system inherently logs issuance and any modifications happen only via separate documents (no silent changes possible).

In summary, KSeF invoices do not require traditional archiving by taxpayers – the system itself is the archive. Taxpayers must ensure access to that system (i.e., maintain their ability to log in and retrieve their data). For invoices or documents outside KSeF, normal retention rules apply (keep for 5 years, ensure integrity, etc.). Poland effectively centralizes invoice retention, which should simplify compliance: companies no longer need to store massive files of invoices or worry about disk failures losing invoice data – the tax authority shoulders that. Nonetheless, prudent businesses will keep backups of critical invoices and still organize their records, especially during the transition when not everything is in KSeF. The bottom line: Invoices in KSeF = no additional archiving obligation on the company (the law explicitly relieves this), Retention period = standard tax period (at least 5 years, effectively 5+1; the system likely stores 10), Storage location = central (with company copies optionally anywhere with proper access), Integrity = guaranteed by digital controls, Audit access = direct through system, and Readability = ensured by tools to view XML. [atl-law.pl] [fonoa.com]

9. Penalties & Enforcement

Poland’s legislation introduces specific penalties for non-compliance with the e-invoicing and e-reporting obligations, though with a grace period initially. Enforcement will ramp up after the transition. Key points on penalties:

Failure to issue a required e-invoice through KSeF: If a taxpayer who is obliged to use KSeF issues an invoice outside the system (for example, issuing only a paper/PDF invoice bypassing KSeF), or fails to issue an invoice at all when required, they can face a financial penalty of up to 100% of the VAT amount shown on that invoice. This is a severe penalty essentially equal to the VAT on the transaction. If the invoice in question did not show VAT (e.g. an exempt or zero-rated invoice), the penalty can be up to 18.7% of the gross amount of the invoice. (The 18.7% figure seems odd but is specified by law – it likely corresponds to 15% of gross in net terms or is tied to a fraction of the VAT that would have been due.) These penalties are outlined in the amended VAT Act (probably Article 106w or similar). In essence, not using KSeF when you should have can cost you an amount equivalent to the VAT on that invoice, effectively nullifying any benefit you might have sought by not reporting it. It’s a punitive measure to ensure compliance. [atl-law.pl]
Late submission after a system outage: The law also covers cases where an invoice was issued offline (due to KSeF unavailability) but then not submitted within the required time after the system comes back. If a taxpayer fails to upload an offline invoice within the deadline (e.g. next business day), this is considered an offense. Similarly, if they issue an invoice in the wrong mode (say the system was actually available but they used offline without reason), that could be penalized. These would likely fall under the same umbrella penalty (failing to properly issue via KSeF). During 2026, however, these specific cases are exempted from penalty (see grace period below). [crido.pl]
Incorrect e-reporting or data errors: If a taxpayer submits an invoice via KSeF but with incorrect data that leads to a VAT underpayment or other issues, existing VAT penalties may apply (just as issuing a wrong invoice pre-KSeF had consequences). However, KSeF’s validations catch many errors up front, reducing this risk. If the JPK_VAT monthly report is filled incorrectly (like failing to include required KSeF references or mis-labeling outside invoices), that is subject to SAF-T penalties (there are fines for errors in SAF-T, typically a small amount per error that can accumulate, or a mandate to correct). The new law likely synchronizes this, perhaps adding penalties for not including KSeF numbers in the records when required. These would be relatively minor compared to the 100% VAT penalty.
Platform non-compliance: This might refer to failing to follow KSeF procedures aside from invoice issuance – e.g., not obtaining a certificate, not maintaining authorization, or misuse of the platform. There isn’t a specific fine for “didn’t integrate system by deadline” beyond the fact that if you don’t integrate, you’ll end up failing to issue invoices, which triggers the above penalties. Using KSeF also means abiding by its rules – for example, if someone tried to game KSeF by issuing dummy invoices or something, general tax anti-abuse rules would apply. Also, Poland’s Penal Fiscal Code could categorize certain deliberate non-compliance as offenses (like if someone intentionally circumvents KSeF to evade tax, that could be tax fraud).
Archiving violations: If a company were to deliberately not keep required records (for those few things outside KSeF) or destroy invoices early, the Penal Fiscal Code has provisions for failing to meet record-keeping obligations. Typically, fines can be imposed for not keeping invoices for the required time or not presenting them. However, since KSeF takes over archiving, this risk diminishes for e-invoices. For non-KSeF invoices, if a company can’t produce them on audit, they might face general sanctions (which could be a fine up to a certain amount).
Intentional vs. negligent errors: Polish law (Penal Fiscal Code) distinguishes intentional tax evasion from technical breaches. Intentional evasion (like not issuing an invoice to hide income) can lead to criminal-fiscal charges – which might include heavy fines or even imprisonment in extreme VAT fraud cases. With KSeF, if a company purposefully avoids using the system to conceal sales, they face both the VAT Act penalty (financial) and potentially charges under the Penal Fiscal Code for unreported sales. Negligent errors (like accidentally using wrong format or missing an upload) during the initial phase likely will be treated leniently (especially in 2026, which is meant to be educational). After the grace period, minor breaches (e.g. forgetting to include the KSeF number on a payment or minor delay) might still be waived if due care is shown, but repeated non-compliance would invite fines. The tax authorities indicated that in the beginning they prefer education over punishment. Indeed, the law explicitly states that no penalties will be imposed in 2026 for KSeF-related lapses to give taxpayers time to adjust. Starting 2027, enforcement will be stricter. [atl-law.pl] [atl-law.pl], [crido.pl]
Post-2026 Penalty Regime: From 1 Jan 2027, the penalty provisions (100% VAT etc.) come fully into effect. So if a company in 2027 issues an invoice outside KSeF or not at all, the tax office can assess the appropriate fine. It’s worth noting that “up to 100%” gives some discretion – it may not always be the full 100%. The actual amount might consider circumstances. The law might set a maximum like 100% and possibly a minimum (say 1,000 PLN or something) but allow the authority to impose, for example, 50% in a particular case. We’ll have to see practical enforcement. But clearly the message is that non-compliance can be very costly.
Penalties for buyers: If a buyer somehow does not comply – e.g., they refuse to accept an e-invoice or demand a paper invoice, there isn’t a specific fine. But a buyer who doesn’t have the invoice in KSeF might lose the right to deduct VAT. For instance, if a supplier failed to put it in KSeF, the buyer technically doesn’t have a proper invoice (though if it was the supplier’s fault, the buyer shouldn’t be punished; however, the buyer may need to ensure they obtain the KSeF invoice to claim deduction). The regulations hint that deducting VAT will require a KSeF invoice. If an invoice wasn’t in KSeF, in an audit the tax office could deny the input VAT until it’s fixed, unless it was under an allowed scenario. So enforcement also comes indirectly: to secure VAT refunds/deductions, businesses must comply with the system.
Article references: The amended VAT Act likely introduced new articles 106n–106q (just guessing numbering) related to KSeF. We know Article 106ni was mentioned in CRIDO – that appears to list situations in 2026 where no penalty (“no sanction under 106n”) applies: specifically, (1) failure to issue via KSeF, (2) failure to issue properly during outage, (3) failure to send after outage in time – those are not penalized in 2026 according to Article 106ni. That implies Article 106n is the one that normally would penalize those, but it’s suspended by 106ni. Indeed, CRIDO states “Article 106ni of the VAT Act” covers the deferred penalties in 2026. So, Article 106n likely sets out the fines (some sources indicate it’s 100% and 18.7% as above). The official Journal of Laws or explanatory notes would confirm the numbering. The law also makes reference that the Penal Fiscal Code still applies in any case of non-issuance or wrong issuance. That means if you completely don’t issue an invoice (which is an offense regardless of KSeF), they can still pursue you under existing law (which has fines proportional to tax underpaid or up to certain multiples). [crido.pl]
Grace Period (Educational enforcement in 2026): As noted, from Feb 1, 2026 until Dec 31, 2026, no administrative fines will be imposed for KSeF violations. The tax authorities have committed to focusing on educating taxpayers during this initial live period. This doesn’t mean one can ignore the system; the law expects you to try to comply, but if you slip up, the tax office should not immediately issue a fine. They may issue a warning or guidance to fix issues. Companies are advised to document their efforts to comply (as CRIDO suggests: keep a “defense file” of steps taken to implement KSeF) to show they acted in good faith even if something went wrong. If a company blatantly ignores KSeF in 2026, while they might not get the specific 100% VAT fine, they could still face trouble (e.g., they wouldn’t have valid invoices, their customers can’t deduct VAT properly, etc., and serious abuse could still trigger general anti-fraud action). But generally for minor non-compliance, 2026 is a soft landing. [atl-law.pl], [crido.pl] [crido.pl]
From 2027 onward, enforcement gets strict: The head of tax office can impose the fines as per the VAT Act. Additionally, the Penal Fiscal Code (PFC) can be invoked for what’s effectively tax offenses. For example, issuing an invoice outside KSeF might be considered issuing an “improper invoice” under PFC, punishable by a fine (the PFC typically has fines for irregular invoicing up to 180 daily rates, etc.). However, likely they will use the administrative penalty (VAT Act) in most such cases, reserving PFC for egregious cases. If a company fraudulently tries to avoid KSeF to conceal sales, this becomes tax evasion – then besides the 100% VAT fine, the company managers could face criminal-fiscal charges. Enforcement will be aided by the fact that the tax authority has much more data in real time to identify discrepancies (for instance, if a company files a VAT return showing sales but there are fewer KSeF invoices than expected, or if buyers report purchases that don’t have matching KSeF records, etc.). This data matching will drive enforcement actions too.
Penalties for Platform misuse: If someone tries to hack or alter KSeF, that’s likely covered by separate IT crime laws. If a taxpayer deliberately issues duplicate invoices or manipulates sequences, the system likely prevents it; if not, such actions would fall under falsification of records. There’s nothing specific in VAT Act for that because KSeF design should eliminate those possibilities.
Official sources on penalties: The Act’s explanatory memorandum indicated a rationale for penalties similar to Italy’s approach (Italy has fines of 100% of VAT for missing clearance invoice, capped at some amount). Poland didn’t specify a cap in the snippet we saw, just percentages. The “100%/18.7%” is in line with earlier proposals. Also, the law mentions relief from penalties if certain conditions (like 2026 timeline) are met. [crido.pl]
Examples: If a company in 2027 fails to issue 10 invoices via KSeF, each having 1,000 PLN VAT, theoretically tax office could impose up to 10,000 PLN penalty on each = 100% * 1,000, totaling 10,000 PLN * 10 = 100,000 PLN. They might consolidate or choose a lump sum – actual practice to be seen. If an invoice had 0 PLN VAT (say an exempt service invoice for 1000 PLN), up to 18.7% of 1000 = 187 PLN penalty for that invoice not via KSeF. These are “up to” – actual could be lower per their judgement.
Other enforcement measures: Apart from monetary fines, non-compliance can lead to business operational issues. For example, not using KSeF means your invoice isn’t valid, so your customer might withhold payment or refuse the invoice, etc. Also, consistent failure might flag you for audits. The system is highly likely to automatically flag companies that stopped sending invoices or have mismatches. So enforcement will not rely solely on penalties, but also on these reputational and business consequences.

In summary, Poland’s enforcement regime is strict but staged: Initially (2026) no monetary penalties while people adjust. From 2027, heavy fines can apply for not issuing via KSeF (up to 100% of VAT on that invoice) or not complying with deadlines. These are in addition to existing penalties for not issuing invoices or for tax evasion under general law. The intention is to strongly deter taxpayers from bypassing the system once the grace period is over. However, ordinary mistakes can be corrected (issue a proper KSeF invoice as soon as discovered, etc.) and likely would not draw the maximum fine if there’s no revenue loss to the government. As always, proactivity is advised: companies should document their implementation efforts, correct issues promptly, and they will likely avoid the worst outcomes.. The legal references for these penalties are in the amended VAT Act (Article 106n and following, with Article 106ni giving the 2026 relief), and the official stance is that enforcement will be educational first, punitive second in the rollout. [atl-law.pl] [crido.pl]

10. Pre-Filled VAT Returns

Poland currently does not provide pre-filled VAT returns to taxpayers, and no immediate change to that has been announced as part of the KSeF mandate. However, the data collected via e-invoicing could pave the way for future pre-filled return initiatives:

No Pre-Population of VAT Returns as of now: At present, Polish VAT taxpayers must file their own VAT declarations (in the form of the JPK_V7M or V7K file, which combines the return and detailed ledger). The tax administration is not yet issuing draft VAT returns for businesses to confirm or adjust (unlike some countries that have started doing this for certain segments). The KSeF system will give the tax authority real-time info on sales and purchase invoices, but Poland has not implemented a system to automatically compute each taxpayer’s VAT liability and send it to them for approval. The onus remains on taxpayers to compile their VAT return each month (or quarter) and submit it via the SAF-T format. In fact, since October 2020, Poland integrated the VAT return into the SAF-T (JPK_VAT with declaration) – so taxpayers are already sending a detailed report including all output and input VAT, which the authorities cross-check but do not pre-fill themselves. [fonoa.com]
Plans or Discussions: The Ministry of Finance has not explicitly announced a “pre-filled VAT return” (sometimes called E-deklaracje draft) in connection with KSeF’s go-live. The focus has been on implementing the infrastructure and rules for e-invoicing. However, the ultimate vision of such e-invoicing reforms often includes leveraging the data for simplifying compliance. With all sales and many purchase invoices in their database, the tax authority theoretically could prepare at least a draft output VAT report for each company. For input VAT, they’d also have data (from suppliers and from import/customs systems), but one complication is: not all input VAT comes from KSeF (imports, some foreign purchases, small receipts, etc., won’t be in KSeF). So fully accurate pre-filling would still require information beyond KSeF (e.g., an import VAT from customs, or self-accounted VAT on foreign services).
Reliance on e-invoice data for future returns: It is expected that over time, VAT reporting will increasingly rely on the e-invoicing data. The EU’s larger project “VAT in the Digital Age” (ViDA) explicitly aims for transaction-based reporting to enable things like pre-filled VAT returns across the EU by the end of the decade. Poland, being an early mover in real-time reporting, could pilot such features sooner. Possibly, once KSeF has been running for some time and data quality is high, the Ministry might introduce a service in the online tax portal to show businesses a summary of their sales and purchase totals as per KSeF for a given period. Already, with SAF-T, the tax authority could cross-check purchase and sales listings to detect discrepancies (they do inform taxpayers of mismatches). Pre-filling would be a next step – e.g., using KSeF to pre-fill the VAT return form fields like total sales, total output tax, total purchases, total input tax. [ec.europa.eu], [ec.europa.eu]
Current requirement – taxpayer input: As of the latest updates, taxpayers still need to manually (or via their software) prepare the VAT declaration portion. That means consolidating any invoices (KSeF or not), applying any adjustments (credit notes, bad debt relief, etc.), and then file the JPK. KSeF may simplify this internally for businesses: many companies may find that since their AR and AP systems are connected to KSeF, they can more easily generate accurate VAT figures. But they still have to do it themselves. The tax office isn’t sending them a “here is your VAT due, please pay by this date” notice.
What data fields could be prefilled: If Poland were to implement pre-filled returns, likely they’d use KSeF sales data to fill in the “amount of sales at 23% VAT = X, VAT = Y; amount of sales at 0% = Z; etc.” because they can categorize each invoice. They could also pre-fill your output VAT total. On the purchases side, they could, in theory, sum up all the purchase invoices you have in KSeF where you are buyer (since they see those too), to suggest your input VAT. But they’d be missing any imports or invoices from foreign suppliers not in KSeF. Those would still require manual addition. Similarly, any adjustments (like corrections for previous periods, or VAT not deductible proportionally, etc.) are not known from raw invoice data and would need manual input. So a pre-filled return likely would never be fully complete – taxpayers would always have to review and add certain info. This is perhaps why Poland hasn’t rushed into it; given that everyone already files via JPK (which is structured and digital), the marginal gain of pre-filling might not be huge until everything is reported in real-time.
Preliminary initiatives: There have been some smaller developments – for instance, the Polish tax portal (e-Urząd Skarbowy) can show some info like VAT account balances, but not a draft of the return. For individual PIT taxpayers, Poland has “pre-filled PIT returns” for some time. But for VAT, not yet.
Future Outlook: The Ministry of Finance has hinted that with KSeF, compliance burden on businesses will reduce, possibly including less detailed returns. It’s conceivable that after a year or two of KSeF, they may simplify the SAF-T requirements or maybe even eliminate the need for taxpayers to list each invoice again in SAF-T (since KSeF provides that). In such a scenario, the “VAT return” might be reduced to a summary that the authority could prepare. However, as of 2026, the SAF-T requirement remains (with modifications for KSeF numbers), so no immediate relief there. [ec.europa.eu], [ec.europa.eu] [atl-law.pl]
ViDA (EU initiative) timeline: The European Commission’s VAT in the Digital Age proposals (if adopted) might mandate digital reporting for cross-border from 2028 and possibly encourage or mandate pre-filled returns by 2030. Poland’s system is well-positioned to integrate with that; by then, we might see a formal move to pre-filled VAT declarations or even elimination of the periodic declaration in favor of continuous reporting.
Which fields pre-filled vs require input: Hypothetically, if Poland offered a pre-filled return now, fields like total taxable sales, total output tax per rate, total exempt sales, would be drawn from KSeF (they know exact amounts). Fields like input VAT claimed would be partially drawn from KSeF (for domestic purchases) but the taxpayer would need to add any missing amounts (like import VAT paid that month, or purchases from small suppliers who perhaps still used cash register receipts). Also, any corrections or special adjustments (like annual proportion calculation for mixed use input VAT) would need manual input. So a taxpayer would always need to verify and possibly edit the draft.
Confirmation vs. editing: If in future it’s implemented, likely taxpayers would log in to the e-Tax Office, see a draft VAT return based on invoices reported, and either accept it as is (if it matches their own books) or modify it (add any missing info or correct errors) before finalizing.
Official stance: The official line as of late 2025 is that taxpayers continue to be responsible for their VAT filings. The tax authority uses the KSeF data to cross-check but not to pre-populate forms for the taxpayer. For example, if a taxpayer forgets to include some output VAT in the return but did issue the invoice in KSeF, the tax authority can catch that discrepancy and likely contact the taxpayer or automatically adjust the assessment. But they aren’t yet sending out a “we think your VAT due is X, please pay that.”

In conclusion, pre-filled VAT returns do not exist in Poland in 2026 – each taxpayer must still compile and submit their VAT return (via JPK file). While KSeF greatly increases the tax authority’s visibility of the underlying data, Poland has not (yet) translated that into a service of providing taxpayers with a completed return. It remains the taxpayer’s job to ensure the VAT declaration is correct, using the data from KSeF plus any other necessary information. There is also no announced plan or date for introducing pre-filled returns; the focus is on making sure KSeF runs smoothly and on using its data to simplify audits and possibly reduce other compliance (for instance, the necessity of certain listings). [fonoa.com]

That said, the perspective beyond 2026 is that the wealth of real-time data could enable the tax authority to prepare at least partial returns in the future. Taxpayers should stay tuned for any developments – for example, the Ministry might at some point say: “Given KSeF, we will no longer require the detailed sales/purchase listings in JPK from 2027” or “We will offer a draft return for your confirmation.” As of the latest information, however, no such measure is active, and taxpayers must continue filing VAT returns in the usual way, carefully integrating their KSeF data and ensuring consistency. The primary reliance on e-invoicing data for now is on the tax administration’s side (to verify compliance), not on automating the taxpayer’s filing process (except that businesses themselves can use the data to automate their internal return preparation, which many will). [ec.europa.eu]

11. Impact on SMEs and Startups

The mandatory e-invoicing mandate in Poland will significantly affect SMEs (Small and Medium-sized Enterprises) and startups. There are both challenges and some benefits for smaller businesses. Let’s break down the impacts, supported by recent analyses and provisions:

Phased Introduction & Support for SMEs: Recognizing that SMEs have fewer resources, the government staggered the rollout so that large companies pioneer the system first. SMEs (those below PLN 200m turnover) get extra two months (mandatory only from April 1, 2026) to observe and prepare, and the smallest businesses (micro companies invoicing under PLN 10k/month) have until Jan 2027. This phased approach is directly aimed at giving SMEs more time to adapt without penalty. Additionally, the Ministry of Finance provided free tools for e-invoicing, which are especially useful for SMEs that may not have sophisticated ERP systems. These free tools include the “KSeF Taxpayer” web application and a mobile app, as well as an updated “e-Mikrofirma” program that small businesses can use to issue and send invoices through KSeF. By offering these, the government reduces the need for an SME to purchase expensive software or hire IT developers – a one-person company can log into the government portal and create invoices at no cost. Training and informational campaigns (“Środy z KSeF” webinars every Wednesday, instructional brochures) have been targeted at SMEs to raise awareness. There is no direct subsidy (no money given to companies for compliance), but these free applications and the delayed enforcement act as indirect support. Also, the grace period with no fines in 2026 is crucial for SMEs – it means they can experiment and learn the system with a lower risk of punishment if they make mistakes. This “soft-landing” policy benefits smaller firms the most, since they might need more trial-and-error initially. [atl-law.pl] [dudkowiak.com], [ksef.podatki.gov.pl] [ksef.podatki.gov.pl]
No Simplified Regime or Threshold Exemption (except temporary): Apart from the temporary exclusion for those under PLN 10k monthly invoicing in 2026, there isn’t a permanent exemption for small enterprises. Even a one-person business or someone under the VAT registration threshold (who voluntarily registered or who must issue an invoice upon request) will have to use KSeF when issuing invoices, by 2027 the latest. So SMEs are fully in scope; Poland decided not to exclude them in the long run so as to maximize the benefits of a unified system. There is also no “simplified invoice” inside KSeF beyond what was already in law (the PLN 450 receipt rule which expires end of 2026). So, SMEs must comply like anyone else. That said, many micro-businesses (like local shops) often don’t issue invoices at all (just receipt to consumers). Those who truly never issue VAT invoices (e.g., fully B2C and below threshold) might not feel a direct impact. But any SME that deals B2B or needs to invoice will be using KSeF. [mddp-outsourcing.pl] [poland-accounting.eu]
Operational Impact – Costs and Process Changes: For SMEs and startups, one of the biggest concerns is the cost of compliance. Larger businesses typically have IT departments or software vendors to handle integration, but an SME might rely on an off-the-shelf accounting program or even manual invoicing. Such businesses may need to upgrade their software or subscribe to a service that supports KSeF by 2026. There could be a one-time cost for software updates (many accounting software providers in Poland are updating their products to interface with KSeF, sometimes charging an update fee). Alternatively, using the free government tools avoids software costs but may be more time-consuming (entering invoices manually on a portal). A recent SME survey (as discussed in tax advisory circles late 2025) indicated many SMEs were unaware of KSeF or had done little to prepare, partly due to fear of complexity and cost. Implementation might require buying a KSeF certificate (~paid to the Ministry, but they appear to be free of charge from Nov 2025, just requiring an application) and possibly better internet/computer equipment for some. [crido.pl]

ERP/Software adaptation: SMEs that use popular accounting platforms (e.g. Subiekt, Optima, enova365, etc.) will receive KSeF functionality in those – likely as part of normal updates or an extra module. Some might need to pay for a newer version or a module license. If an SME uses custom billing (like Excel templates), they will now need to transition to an electronic format – either using the free tools or adopting an invoicing software. This is a learning curve and potentially a monetary expense. The time investment is also notable: owners/staff have to learn the new system, possibly attend trainings, and adjust internal workflows (for example, no more printing invoices to send to clients; now they must ensure clients know to retrieve from KSeF or send a courtesy PDF).

However, after the initial adjustment, many routine tasks could become easier. For example, an SME that manually emailed invoices and then tracked if the client got them might save time – since once it’s in KSeF, the invoice is deemed delivered, they don’t have to follow up on sending. Also, no need to archive physical invoices – that reduces storage overhead (SMEs had to keep files of invoices; now KSeF does it). Some SMEs might reduce paper and printing costs entirely. [mddp-outsourcing.pl] [atl-law.pl]

There is also an operational consideration that every SME must ensure it can receive invoices via KSeF. For a small company without a dedicated finance department, remembering to log in and download purchase invoices might be new. They may consider delegating that to their accountant or setting up the mobile app with notifications. The Ministry’s materials include flyers for SMEs on “How to receive an invoice in KSeF?”. This indicates a push to educate small firms that, e.g., their electricity or phone bills from large providers will now appear in KSeF, and they need to retrieve them. Initially, this could lead to confusion – a risk is that a startup might not check KSeF and could miss invoices, impacting bookkeeping. Over time, though, it will likely integrate (accountants will routinely check or software will auto-fetch). [ksef.podatki.gov.pl]
Cash Flow Effects: One positive impact cited is faster VAT refunds. The government committed that using KSeF entitles the taxpayer to a VAT refund in 40 days instead of the standard 60 days. This incentive was already in place for voluntary users and will apply to all once mandatory. For SMEs and startups, which often are more cash-sensitive, getting VAT refunds 20 days earlier is beneficial for cash flow. It’s essentially three weeks less waiting for money tied up in VAT credits (for example, export-oriented startups or those investing in equipment can recoup VAT faster). Additionally, earlier error detection thanks to real-time reporting can improve cash flow management; if an SME makes a mistake on an invoice, they’ll know (through rejection) immediately and can fix it, rather than discovering months later and possibly facing penalties or lost deductions. Also, because invoices are delivered instantly to buyers, one could argue SMEs might get paid faster (no postal delays, no “we never received the invoice” excuses). It’s easier to prove the customer has the invoice (it’s in KSeF). On the flip side, if an SME isn’t timely in issuing invoices via KSeF, that could delay their payment – but that’s an internal discipline matter. [atl-law.pl]

Another cash-flow related concern: Real-time tax oversight could mean less room for delaying VAT remittance. Some SMEs historically might issue an invoice late or backdate to manage when VAT is due. KSeF makes that nearly impossible (authorities see the timestamp). This might tighten cash flow for those who previously took advantage of float, but it’s about enforcing timely tax payment. Overall, law-abiding SMEs shouldn’t see negative cash flow, and they gain the refund speed benefit.
Administrative Burden vs Simplification: For SMEs, there’s an initial increase in administrative burden – they must implement new procedures, possibly coordinate with their external accountants differently (no more sending a shoebox of paper invoices, but rather granting the accountant access to KSeF data). There might be training required for staff on how to issue or retrieve invoices in the new system. Some very small businesses that do not have in-house accountants will rely on accounting offices – those offices now need to get authorization to access their clients’ KSeF accounts or receive invoices. Accountants might charge a bit more for the extra work initially. However, once established, many processes become easier or even automated: e.g., an SME’s bookkeeping can be simplified by directly importing structured invoices from KSeF into their accounting software (no manual data entry from paper invoices). This is a big efficiency gain. Purchase invoice data can flow into accounting systems automatically, reducing manual input and errors. SMEs thus could experience more automation in accounting, which is a long-term efficiency win. Also, they no longer need to devote effort to archive invoices (either physically or ensuring digital ones meet criteria) – KSeF stores them, so administrative burden of maintaining archives is lifted. [dudkowiak.com] [atl-law.pl]

The net effect likely is: short-term increase in workload (setup, learning) and long-term decrease in routine work (data entry, archiving, error correction). A tax partner at a consulting firm noted that after the learning curve, many companies, including SMEs, will benefit from smoother invoicing and less clerical work in invoicing and reporting.
Market Competitiveness & Early Adopter Advantage: Startups and tech-savvy SMEs that adapt quickly to KSeF could turn compliance into an advantage. For instance, those who integrate KSeF early can offer seamless e-invoicing to their clients (which might be appreciated by larger clients who prefer structured invoices). They also iron out any issues ahead of competitors. Early adopters might have had access to the voluntary phase incentives and be well-prepared now. By contrast, SMEs that procrastinate may find themselves rushing in Spring 2026, possibly disrupting their operations or risking mistakes. There’s a competitive element: by 2027, every compliant business will use e-invoicing, but the transition period could be smoother for some than others. Also, the digitalization push may encourage SMEs to upgrade other systems (maybe adopt an ERP or at least digital record-keeping) which can improve their overall efficiency and insight into their business.
Interoperability Challenges for smaller systems: Large companies often have dedicated IT teams to ensure their systems talk to KSeF seamlessly. Smaller companies might use multiple disparate systems. Ensuring that their billing, accounting, and CRM systems all handle KSeF properly might be challenging. For example, a small business’s inventory management software might need an update to trigger a KSeF invoice when a sale is made. If vendors of small-business software lag in introducing KSeF capabilities, those SMEs might have to resort to manual processes (like generating the invoice manually on KSeF platform then recording it back in their system). This could lead to inefficiencies or errors if not managed. Over time, software solutions will catch up, but there could be a period where SMEs juggle different tools.
SME Readiness Assessments: According to advisory surveys in late 2025, many SMEs were still unprepared. For example, an article noted that not every organization will fully prepare by the deadline due to vendor delays or limited resources, which specifically calls out smaller companies. To mitigate that, experts advise SMEs to document their efforts (“defense file”) to show they tried to comply in case they aren’t fully ready by Feb/Apr 2026. The government has acknowledged these concerns by delaying the mandate and promising leniency in 2026. The Big Four and local consulting firms have been publishing guides directed at SMEs to help them navigate this (simplifying the technical language, offering checklists). The sentiment on the ground is that while large firms are mostly ready, a lot of SMEs will be scrambling around Q1 2026. For startups established only recently, they have to implement this from the get-go, which might actually be easier since they can build it into their processes from day one (no legacy systems to change). [crido.pl]
SME Benefits from Government/EU programs: There aren’t direct subsidies in Poland for e-invoicing, but on an EU level, digitalization funds exist (Poland’s Recovery Plan included some funding for SME digital tools, which could indirectly help in adopting e-invoicing solutions). Additionally, because e-invoicing is becoming standard across the EU, Polish SMEs that adapt now may find it easier to do business with foreign partners who also use e-invoices (e.g., Italy, France soon, etc.), potentially opening new markets or simplifying cross-border trade in the future.
Administrative burdens vs simplifications summary: Initially, SMEs will likely feel a burden: needing to learn KSeF, possibly invest in software or spend time issuing invoices through a new system, adjusting agreements with accountants, and ensuring compliance. There could be some productivity loss during the transition. After that, simplifications kick in: no need to manually send invoices, no lost invoices, easier bookkeeping (since invoices can be downloaded rather than typed in), and no worries in case of an audit about finding old invoices (they are all in KSeF). For example, one SME practitioner noted that preparing the monthly VAT return should become quicker when most invoices auto-populate – reducing time spent and consulting costs in the long run. [atl-law.pl]
Digitalization Requirements & Market Impact: The mandate essentially forces all SMEs to digitalize their invoicing. Some smaller businesses that were very paper-based will have to go digital, which can be challenging but ultimately keeps them competitive in an increasingly digital market. It levels the playing field in some ways – even very small firms will produce machine-readable e-invoices, which modernizes the B2B ecosystem. Interoperability challenges might occur if an SME’s customer or supplier is not fully on board (though with mandate, all should be). Possibly in early 2026, a large company might issue via KSeF and a small trading partner may be confused about how to get it – but that is what the educational push addresses. Over time, everyone will use the unified method, reducing friction. Manual processes will diminish; SMEs relying on manual invoice entry will need to shift to digital, which could be momentarily hard for some workers but ultimately beneficial skill-wise.
Potential advantages for SMEs:
- Fewer tax audits or quicker audits: With KSeF data, tax authorities can verify a lot without a lengthy on-site audit. SMEs often fear disruptive audits; if much is verified automatically, compliant SMEs might experience fewer audits or at least shorter ones, which saves them time and stress.
- Reduced errors: The validation by KSeF means an SME’s invoice mistakes (like calculation errors) get caught instantly, allowing correction. This prevents issues down the line that might cause customer disputes or audit findings. [atl-law.pl]
- Better invoice management: SMEs get a government-provided repository of all their issued and received invoices. For a small business owner, this could simplify finding old invoices or tracking what’s paid/unpaid (some visibility improvements, though KSeF is not an accounting software, the data can be used by their systems to track statuses).
SME Readiness assessments: The government and EU have noted the need for readiness. The EU’s 2025 country factsheet for Poland mentions that Poland is ensuring KSeF aligns with future requirements and provides free tools, indirectly acknowledging the need to help SMEs. Organizations like chambers of commerce in Poland have held sessions to help SMEs prepare (with Big4 participation). Broadly, SMEs that treat this as an opportunity to modernize can come out more efficient, whereas those that delay will face a hectic transition. [ec.europa.eu]

In sum, SMEs and startups will undergo a digital transformation due to KSeF. There may be initial costs and learning curve – setting up IT solutions, possibly hiring outside help to integrate systems, training staff, and altering some workflows. The mandate does not exclude them, so they must comply fully, but the staged timeline and free support tools are meant to ease it. Once through the transition, SMEs should benefit from faster VAT processes (notably quicker refunds), less paperwork (no need to store or print invoices), and improved accuracy and automation in invoicing and accounting. Over the longer term, this could reduce administrative overhead and allow small business owners to spend less time on invoicing and tax compliance and more on their core business. The challenge is ensuring that during 2026, SMEs get the help they need to implement KSeF correctly – through the grace period and available guidance, Poland is giving them that buffer to get up to speed. [crido.pl] [dudkowiak.com], [mddp-outsourcing.pl] [atl-law.pl] [atl-law.pl], [crido.pl]

12. Official References

For further authoritative information and guidance on Poland’s e-invoicing and e-reporting system, refer to the following sources (all up-to-date as of 2025–2026):

Ministry of Finance – KSeF Official Website: The Polish Ministry of Finance’s dedicated KSeF portal provides official documentation, user manuals, FAQs, and technical specifications for the e-invoicing system (including the FA(3) schema information sheet in English). (URL: ksef.podatki.gov.pl). This is the primary source for how KSeF works and how to use it. [ksef.podatki.gov.pl]
Legislation – Polish VAT Act Amendments: The legal basis for mandatory e-invoicing is set out in the Act of 5 August 2025 (amending the Act on VAT and the Act on National e-Invoice System). The text (in Polish) can be found in the Journal of Laws (Dz.U. 2025 poz. 1598). It outlines the phased implementation dates and new Articles 106nb–106nd regarding KSeF requirements. Additionally, the earlier Act of 16 June 2023 (Dz.U. 2023 poz. 1421) and the Act of 9 May 2024 delayed the original dates. Together these laws form the legislative backbone of KSeF. [poland-accounting.eu], [poland-accounting.eu] [ec.europa.eu]
Implementing Regulations (Ministry of Finance, Dec 2025): Four Ministerial regulations detail operational aspects: (1) cases exempt from issuing e-invoices (Journal of Laws 2025, item 1740), (2) revised invoicing rules (item 1742), (3) use of KSeF (item 1815), and (4) changes to JPK_VAT reporting (item 1800). These were signed on 7 and 12 December 2025. They can be accessed via the Government Legislation Centre’s website (legislacja.rcl.gov.pl) or the official law database (ISAP) for the specific item numbers. They cover things like offline mode conditions, authorization (ZAW-FA) procedures, the new invoice markings (OFF/BFK/DI), etc. [getsix.eu], [getsix.eu] [getsix.eu]
EU Council Implementing Decision (EU) 2022/1003: This is the decision by the EU Council authorizing Poland to implement mandatory e-invoicing (derogating from the VAT Directive). It was adopted on 17 June 2022. It’s an important reference as it sets the period of derogation (2024–2026) and conditions (like ensuring acceptance of EN16931 format) which Poland’s system follows. Available on EUR-Lex under document number 32022D1003. [ec.europa.eu]
Technical Documentation – FA(3) Schema and API Specs: The Ministry of Finance has published the full Logical Structure FA(3) and API documentation for KSeF 2.0. The “Information sheet on the FA(3) logical structure (version 1)” in English is available on the official KSeF site. It describes the XML format fields. The API specification (in Polish, “Swagger” docs, etc.) can be found on the KSeF portal’s download section. These are essential for IT teams implementing integration. [ksef.podatki.gov.pl]
Polish Government Tax Portal (e-Urząd Skarbowy): General information and news releases about KSeF can be found on the e-Tax Office portal. For instance, press releases in late 2025 confirming the postponement to 2026 and urging businesses to get ready. While mostly in Polish, key announcements are summarized in English by major firms (see below).
Tax Authority Guidance & Brochures: The Ministry has issued user guides (Podręcznik KSeF cz. I–IV) and held webinars (“Środy z KSeF”). Summaries of these (in Polish) and PDF slides are posted on the KSeF site. They contain practical steps for registration, using certificates, issuing invoices, etc. These are official educational materials from the tax authority. [ksef.podatki.gov.pl]
Big 4 and Law Firm Newsletters: Several large tax advisory firms have published detailed alerts summarizing the Polish e-invoicing rules:
- EY Global Tax Alerts: “Poland postpones implementation of mandatory e-invoicing system” (Jan 2024) and “Poland MoF updates obligatory e-invoicing regulations” (28 April 2025). These discuss timeline changes and key provisions (like penalty deferral, offline mode, B2C optional) and are available on EY’s Tax News site. [taxnews.ey.com], [taxnews.ey.com]
- KPMG TaxNewsFlash: “Poland: New KSeF manual to support mandatory e-invoicing implementation” (25 Sept 2025). This outlines the release of updated guidance (manual) and confirms the Feb/April 2026 dates and authentication methods, etc. [kpmg.com]
- Deloitte / BDO / PwC updates: e.g., BDO Indirect Tax News (July 2024) which explained the reasons for the system’s delay and proposed changes. PwC Poland’s website also has a dedicated KSeF page with explanations in English. [bdo.global]
- Local Polish tax blogs: e.g., “Invoicing in Poland 2025: VAT and Mandatory E-invoicing via KSeF” by Intertax (Piotr Kawa, Oct 2025) and law firm articles (Dudkowiak & Partners, MDDP, Crido blogs) – these provide practical guides and are good for understanding nuances and preparation tips. For example, the ATL Law “Guide for 2026” (Dec 29, 2025) and Crido’s blog (Jan 20, 2026) about last-minute prep are useful (though unofficial, they cite official info). [atl-law.pl], [crido.pl]
These newsletters summarize and often link to the official laws and regulations, making them a convenient reference with expert commentary.
Government Portals:
- Platforma Elektronicznego Fakturowania (PEF): For B2G e-invoicing background; since PEF will integrate with KSeF, info can be found on the gov.pl site for PEF.
- Ministry of Finance announcements: The Polish Ministry of Finance (mf.gov.pl) news section posted announcements on e-invoicing (for example, on Dec 11, 2025, confirming no further delays). Checking the Ministry’s official communications can provide confirmation straight from the source (in Polish).

Each of these sources provides valuable, up-to-date insights or rules:

Legal texts ensure you have the exact mandates and dates. [poland-accounting.eu], [getsix.eu]
Government guides ensure you follow the correct procedures in practice. [ksef.podatki.gov.pl]
International and local tax advisories give context, interpretation, and often unofficial English translations or summaries of key points (like scope, penalties, etc.). [taxnews.ey.com], [kpmg.com]

Using these references, businesses can get both the official requirements and practical advice for implementing Poland’s e-invoicing and e-reporting framework. All links above lead to publicly accessible sources: either government websites or professional publications that are kept updated as the mandate evolves.

13. Summary

Poland is introducing a comprehensive electronic invoicing (e-invoicing) and reporting system (KSeF) that will revolutionize VAT compliance from 2026 onwards. In summary:

Scope: Virtually all B2B and B2G transactions involving Polish VAT taxpayers must go through the KSeF e-invoicing platform. This includes domestic sales and cross-border sales by Polish businesses (intra-EU supplies, exports) – these invoices will be issued as structured e-invoices via KSeF. B2C invoices are not mandated (businesses can continue using receipts or paper for consumers, unless they opt in). Special cases like self-billing and reverse-charge invoices are handled within KSeF’s framework, so long as a Polish entity is issuing the invoice. Only a few document types are exempt (e.g. certain transport tickets, toll receipts, OSS scheme invoices). In short, if a Polish VAT-registered business must issue an invoice, it will do so through KSeF in a standardized digital format. [dudkowiak.com] [grantthornton.pl] [ec.europa.eu], [taxnews.ey.com] [getsix.eu], [grantthornton.pl]
Timeline: After a voluntary phase (2022–2025) and some delays, the mandatory rollout is set in three stages: Large companies (2024 turnover > PLN 200M) from 1 February 2026, all other VAT payers from 1 April 2026, and a grace until 1 January 2027 for the smallest micro-businesses (monthly sales ≤ PLN 10k). These dates are now confirmed in law. During 2026, a “soft landing” applies – no fines for non-compliance in 2026, and certain small issuers can temporarily still use paper invoices that year. By 2027, however, all businesses must be using KSeF for invoices, with no general exemptions. Key milestones: President’s sign-off in Aug 2025, system go-live Feb 2026, full enforcement from 2027. [atl-law.pl] [atl-law.pl], [poland-accounting.eu] [atl-law.pl], [taxnews.ey.com] [atl-law.pl], [atl-law.pl]
Key Obligations: Businesses will be required to issue all sales invoices in a structured XML format via the central KSeF platform. Invoices must be transmitted to the tax authority in real time (or immediately after issuance) and will receive a unique KSeF ID and timestamp. Buyers must retrieve their invoices from the system – meaning companies also must be able to receive invoices through KSeF (either via API integration or by logging into the KSeF web portal). Companies need to adjust their processes: no more emailing PDF invoices for domestic B2B; instead, invoices are considered delivered once posted in KSeF. In addition, monthly VAT reporting (SAF-T) remains but is augmented – each invoice’s KSeF number or a code for outside-KSeF must be included in records. Businesses must also maintain the ability to issue invoices during downtime (by using the allowed offline mode with subsequent upload). There’s a requirement to authorize any third parties (accountants, service providers) who will issue or access invoices on your behalf (via the ZAW-FA authorization process). Importantly, all invoices must adhere to the official schema and content rules – otherwise KSeF will reject them, so data quality is a must. [dudkowiak.com] [bdo.global] [mddp-outsourcing.pl] [atl-law.pl]
Main Risks: The introduction of mandatory e-invoicing brings some risks that companies need to manage:
- Non-compliance penalties: From 2027, failing to issue an invoice through KSeF when required can trigger heavy fines – up to 100% of the VAT on that invoice. So the risk of not adapting in time is financial and reputational. Taxpayers must ensure their systems are ready, or face sanctions and potential loss of VAT deduction rights for their customers (which could disrupt business relationships). [atl-law.pl]
- Operational disruptions: If a company’s invoicing software is not properly integrated or there are mistakes in using KSeF, it could lead to invoices not getting issued (and consequently cash flow delays or compliance issues). There’s also a risk of initial confusion, especially for smaller traders, in handling the new process – e.g., buyers missing invoices because they didn’t realize they must check KSeF.
- Data security and continuity: While KSeF is expected to be robust, companies should have contingency plans (the law provides an offline mode) for any outages. Ensuring authorized access to KSeF (managing certificates, tokens) is critical – losing access could mean inability to invoice until resolved.
- Transition period issues: Businesses that don’t train staff or update procedures may face errors in the early days – e.g., duplicate invoicing or forgetting to send offline invoices once online, which could cause compliance problems. Fortunately, 2026 is forgiving in terms of penalties, but the risk is internal chaos or customer dissatisfaction if invoices aren’t handled properly.
SME Implications: Small and medium enterprises and startups will need to modernize their invoicing processes on a perhaps tighter budget and with less IT support than big firms. Initially this is a challenge – many SMEs are concerned about costs of software upgrades and the complexity. However, the government’s free tools and phased rollout help. In the longer run, SMEs stand to gain from the system: less paperwork, fewer manual errors, and faster VAT refunds (40 days instead of 60) which improves their cash flow. The mandate forces SMEs to digitalize, which can increase their efficiency and integration into supply chains. There’s also an equalizing effect: all companies big or small must comply, so SMEs who adapt quickly won’t be at a disadvantage – in fact they might partner more easily with large businesses thanks to standardized e-invoices. Key for SMEs is to use the 2026 grace period to learn and get help (from software providers or accountants) so that by 2027 they are compliant without last-minute stress. The policies (no penalties in 2026, micro-business deadline 2027) clearly show consideration for SME readiness. [crido.pl] [atl-law.pl] [atl-law.pl], [mddp-outsourcing.pl]
Critical Dates & Next Steps:
- Now–Jan 2026: Final preparations. Businesses should ensure their invoicing software is KSeF-compatible (or plan to use the government’s application), obtain any necessary KSeF certificates or set up qualified signatures, and train relevant staff. Large companies should be in testing mode if not already – the KSeF test environment is available. [atl-law.pl]
- 1 Feb 2026: Mandatory e-invoicing goes live for large enterprises – these companies must start issuing all new invoices via KSeF from this date. All companies, regardless of size, must from this date be capable of receiving invoices from KSeF (since their large suppliers will be sending them). We enter the new regime’s first stage. [atl-law.pl] [mddp-outsourcing.pl]
- 1 Apr 2026: All remaining VAT-registered businesses begin mandatory e-invoicing. By this point, every active VAT taxpayer except the micro threshold ones should exclusively use KSeF for invoices. This is the broadest wave – many SMEs will effectively join at this milestone. [atl-law.pl]
- Throughout 2026: Grace period – authorities will not levy fines for mistakes or non-use, but taxpayers should not be complacent. Use this time to fix any system issues, and develop stable processes (including how to handle offline invoicing when needed). The tax authority will likely monitor compliance rates and reach out with reminders or guidance rather than penalties. It’s advisable for companies to document their compliance efforts in 2026 (to show auditors they tried their best). [crido.pl]
- 1 Jan 2027: Full enforcement begins. All businesses, including the smallest, are now under mandate, and the tax authorities will start applying penalties for breaches. Also, transitional allowances (like using cash register receipts as invoices, or the 10k PLN monthly exemption) expire. At this point, Poland will have an end-to-end e-invoicing system for all B2B transactions. Companies should enter 2027 confident in their KSeF procedures because the “safe harbor” period is over. [atl-law.pl] [taxnews.ey.com]

Overall, Poland’s e-invoicing and e-reporting framework is a major digital transformation of VAT administration, aiming to reduce fraud and streamline tax processes. Businesses must adapt by integrating new technology and protocols into their billing routines. Those that prepare diligently will find that after the initial adjustment, compliance becomes easier (with less manual paperwork) and the tax system more transparent. The next steps for businesses are to finalize implementation (software setup, user training, possibly consulting with tax tech experts) in line with the above timeline, and to utilize the resources provided (official manuals, test environment, and advisor insights) to ensure a smooth transition into this new era of fully electronic invoicing. The message from authorities is clear: KSeF is coming, the deadlines are set, and it’s time to get ready – but ample support and a transition period are in place, so businesses that act now should be well-positioned to comply and even benefit from Poland’s e-invoicing revolution. [taxnews.ey.com], [kpmg.com] [atl-law.pl], [crido.pl]

Key resources