Self-Billing Under KSeF: Who Bears the Sanctions Risk from 2027?

Summary

Self-billing remains permitted under Poland’s mandatory KSeF, but the operational requirements have changed dramatically: the seller must approve the invoice XML before it is submitted to KSeF, and both parties must formalise the arrangement through a detailed written agreement with a clear acceptance procedure. [getsix.eu], [invoicedat…action.com]
From 1 January 2027, full administrative penalties apply — up to 100% of the VAT amount on the invoice, or 18.7% of the gross invoice value for zero-VAT invoices — for any invoice issued outside KSeF, including self-billed invoices that do not meet KSeF requirements. [ksefeo.pl], [sprytnafirma.pl]
When a foreign buyer makes a self-billing error on behalf of a Polish seller, the Polish seller bears the primary sanctions risk, since Polish VAT law treats the seller as the taxpayer responsible for the invoice — even though the buyer physically issued it. This creates a major governance challenge for cross-border self-billing arrangements from 2027 onwards. [edgp.gazetaprawna.pl], [invoicedat…action.com]

Article

Self-Billing Under KSeF: Same Concept, New Reality

Self-billing (samofakturowanie) — where the buyer issues a VAT invoice on behalf of the seller — remains legally permissible under Article 106d(1) of the Polish VAT Act. The mechanism is widely used in high-volume procurement: retail chains settling with hundreds of suppliers, automotive manufacturers paying component sub-suppliers, shared-service centres, and intra-Community supply arrangements. [invoicedat…action.com]

However, the introduction of mandatory KSeF (from 1 February 2026 for the largest taxpayers, and 1 April 2026 for all VAT-registered businesses) has fundamentally changed the operational reality. What was once a paper-and-PDF workflow now requires integration with KSeF’s authorisation model, the structured FA(3) XML schema, and — critically — a pre-issuance acceptance step by the seller. [howtopoland.com] [invoicedat…action.com]

Three conditions must be met for self-billing to be lawful:

A prior written agreement between buyer and seller, specifying the scope of transactions, duration, and termination conditions.
A defined acceptance procedure — the Polish Ministry of Finance interprets this strictly: the seller must approve the XML content before the invoice enters KSeF.
Full compliance with Article 106e invoice content requirements, including the mandatory annotation “Samofakturowanie” (field P_17 set to “1” in the XML). [invoicedat…action.com], [getsix.eu]

The KIS Ruling of 27 February 2026: A Stricter Standard

The individual tax ruling issued by the Director of the National Revenue Information (KIS) on 27 February 2026 (ref. 0112-KDIL1-3.4012.874.2025.2.KK) marked a significant tightening of the interpretative position. The taxpayer had proposed two approaches — approving the invoice after submission to KSeF, or approving a PDF draft rather than the XML file. The tax authority rejected both. [getsix.eu]

The KIS position is clear:

Approval must occur immediately before the invoice enters KSeF.
What is presented for approval must be the XML content, not a PDF visualisation.
Approval may be active or passive (silence = consent), but the procedure must be contractually defined and demonstrable. [getsix.eu]

This ruling is an individual interpretation, not universally binding law — but it signals the direction of future audits and may shape enforcement practice from 2027 onward. [getsix.eu]

The Sanctions Regime from 1 January 2027

2026 serves as a transitional period — administrative penalties under Article 106ni of the Polish VAT Act are suspended until 31 December 2026, giving businesses time to adapt. However, the Fiscal Penal Code (Kodeks Karny Skarbowy, Art. 62) already applies in 2026 for intentional violations such as fictitious invoices. [sprytnafirma.pl], [crowe.com]

From 1 January 2027, the full penalty regime takes effect:

Violation	Maximum Penalty
Invoice issued outside KSeF despite obligation	Up to 100% of the VAT shown on the invoice
Invoice without VAT issued outside KSeF	Up to 18.7% of the gross invoice amount
Failure to upload offline invoices to KSeF within the required deadline	Same scale as above
Fiscal Penal Code liability (intentional violations)	Up to 720 daily rates (potentially up to PLN 44.8 million)

Penalties are imposed by the tax authority through an administrative decision — not automatically. Evidence of due diligence (documented procedures, logs, monitoring, and clear responsibilities) matters significantly. [ksefeo.pl], [sprytnafirma.pl]

Self-Billing and Sanctions: Who Is Liable?

This is the central question raised by Dziennik Gazeta Prawna: when a self-billed invoice is issued incorrectly — outside KSeF, in the wrong format, or without proper approval — who faces the sanctions? [edgp.gazetaprawna.pl]

The answer under Polish VAT law points primarily to the seller (the taxpayer on whose behalf the invoice is issued). The logic is as follows:

Under Article 106d, the seller authorises the buyer to issue invoices in the seller’s name and on the seller’s behalf. The invoice remains the seller’s tax document.
The KSeF authorisation granted via the ZAW-FA form is the seller’s act — the seller delegates the right to issue invoices in the system.
Administrative penalties under Article 106ni are directed at the taxpayer obliged to issue the invoice through KSeF — which, in a self-billing scenario, is still the seller. [edgp.gazetaprawna.pl], [invoicedat…action.com]

This creates a governance paradox: the seller bears the penalty risk, but the buyer controls the operational process of creating and submitting the invoice. If the buyer issues the invoice outside KSeF, uses an incorrect format, or fails to follow the pre-approval procedure, it is the Polish seller who faces potential sanctions from the tax authority.

The Cross-Border Complication: Foreign Buyer, Polish Seller

The risk is amplified in cross-border self-billing. When a foreign buyer (e.g., an EU-based entity) issues invoices on behalf of a Polish seller, several structural problems arise:

The NIP authorisation catch-22: KSeF authorisation requires the seller’s Polish NIP via the ZAW-FA form. If the buyer is the foreign party, the buyer may not be registered for Polish VAT and may struggle to interact with KSeF directly. But more critically, the Polish seller must grant proper KSeF permissions, and the foreign buyer must have the technical capability to submit compliant XML to the system. [invoicedat…action.com]
Responsibility mismatch: The foreign buyer may not fully understand or comply with Polish KSeF requirements, yet the Polish seller bears the sanctions risk if invoices are issued incorrectly or outside the system from 2027. [edgp.gazetaprawna.pl]
No retroactive cure: Once an invoice enters KSeF (or fails to enter it), there is no mechanism to retroactively fix the compliance failure. An invoice issued outside KSeF by a foreign buyer when it should have been submitted through the system creates an immediate penalty exposure for the Polish seller. [ksefeo.pl]

What Should Businesses Do Now?

Given that 2026 is a penalty-free window but not a risk-free one, businesses using self-billing should take concrete steps:

Review all self-billing agreements — ensure they reflect the KSeF reality: pre-issuance XML approval, clear acceptance timelines, dispute resolution, and correction invoice handling. [getsix.eu]
Implement a documented pre-approval workflow — whether active or passive, the seller’s acceptance of the invoice content before KSeF submission must be traceable and auditable. [getsix.eu]
Address cross-border arrangements explicitly — for foreign buyers issuing on behalf of Polish sellers, assess whether voluntary Polish VAT registration, issuing outside KSeF (with risk monitoring), or an alternative invoicing model is the most appropriate path. [invoicedat…action.com]
Clarify internal responsibilities — define who issues, who approves, who submits to KSeF, who monitors status, and who acts if something fails. From 2027, the ability to demonstrate due diligence will be the primary defence against penalties. [ksefeo.pl]
Consider applying for an individual tax ruling if your self-billing model deviates from the most conservative interpretation. [getsix.eu]

The Broader Picture

Granting KSeF authorisation to a buyer for self-billing purposes does not mean that all invoices from that buyer must be self-billed — the authorisation only enables the mechanism; it does not mandate its use for every transaction. [edgp.gazetaprawna.pl]

For multinational companies, the interaction between KSeF self-billing requirements and the upcoming EU ViDA framework remains an open question. ViDA may eventually reduce cross-border e-invoicing authorisation barriers, but it is not a near-term fix for the Polish-specific NIP and KSeF authorisation challenges. [invoicedat…action.com]

The bottom line: self-billing under KSeF is not broken, but it is no longer simple. From 2027, the cost of getting it wrong — potentially 100% of the VAT on every affected invoice — makes it a boardroom-level compliance topic, not just an accounting convenience.

🔗 Sources & Further Reading