Why KSeF Should Not Affect Self‑Invoicing Policies

Summary

Recent practice of the Head of the Polish National Revenue Administration (KAS) adopts an overly restrictive interpretation of self‑invoicing under KSeF, potentially denying VAT deduction where certain formal expectations are not met.
This approach lacks a clear legal basis in the Polish VAT Act and KSeF regulations, which do not fundamentally alter the legal nature or acceptance mechanism of self‑invoicing.
KSeF should be seen as a technical transmission and validation system, not as a tool to redefine substantive VAT rights such as invoice acceptance or input VAT deduction.

Article

At the end of February, the Director of the National Tax Administration (KAS) adopted a very strict position on the acceptance of invoices issued under self‑invoicing arrangements within the framework of Poland’s National e‑Invoicing System (KSeF). According to this approach, deficiencies identified in the self‑invoicing process may result not only in the invoice being considered improperly accepted, but also in a denial of the right to deduct VAT. This stance has raised serious concerns among taxpayers, particularly because it is difficult to reconcile with the applicable VAT regulations.

Self‑invoicing remains a substantive VAT concept

Under Polish VAT law, self‑invoicing is a long‑established mechanism whereby the purchaser issues invoices on behalf of the supplier, subject to a prior agreement and acceptance procedure. The core legal elements of self‑invoicing are therefore contractual and substantive, not technical. KSeF, by contrast, was introduced as a digital infrastructure to standardise the issuance, transmission, and storage of invoices. Its purpose is to facilitate compliance and improve data quality—not to redefine VAT concepts that already functioned under paper or electronic invoicing regimes.

Importantly, neither the Polish VAT Act nor the KSeF‑specific provisions explicitly modify the conditions under which self‑invoicing is deemed valid or accepted. Acceptance of a self‑invoice continues to depend on the agreement between the parties and the actual business reality of the transaction. Treating KSeF validation or procedural steps as decisive for substantive VAT consequences stretches the system beyond its legal intent.

Acceptance of an invoice versus technical processing in KSeF

The restrictive interpretation taken by KAS seems to conflate technical acceptance within KSeF with legal acceptance of an invoice for VAT purposes. KSeF performs automated checks and assigns a reference number, but this should not be equated with a taxpayer’s confirmation that an invoice correctly reflects an underlying supply.

VAT case law at both national and EU level consistently confirms that the right to deduct VAT is a fundamental principle, which may only be restricted in cases of fraud, abuse, or clear breaches of substantive conditions. Purely formal shortcomings—especially those related to a relatively new IT system—should not, in themselves, justify refusal of input VAT deduction where the taxable transaction genuinely took place and tax has been correctly charged.

Risk of disproportionate consequences

If the tax authorities’ strict view were to prevail, businesses using self‑invoicing could face disproportionate risks, particularly in the early years of KSeF implementation. Minor procedural imperfections could trigger severe VAT consequences entirely unrelated to tax loss. Such an approach undermines legal certainty and runs counter to the principle of VAT neutrality, which requires that compliant taxpayers are not penalised for technical defects.

Moreover, self‑invoicing is commonly used in complex supply chains, including retail, energy, and logistics sectors. Introducing uncertainty around VAT deductibility in these models could disrupt established processes and discourage the use of self‑invoicing—despite its recognised efficiency and compliance benefits.

KSeF as an enabler, not a gatekeeper of VAT rights

From a systematic perspective, KSeF should be treated as a technical enabler of invoicing, not as a gatekeeper that conditions substantive VAT rights. While taxpayers must of course comply with KSeF requirements, failure or delay in meeting certain technical expectations should be addressed through proportionate administrative measures—not by denying VAT deduction altogether.

A more balanced interpretation would align KSeF with existing VAT principles and recognise that self‑invoicing policies, properly documented and contractually agreed, remain valid irrespective of the digital channel used to issue the invoice.

Conclusion

The strict stance recently adopted by the National Tax Administration risks attributing to KSeF a legal role it was never intended to play. In the absence of explicit legislative changes, there is no sufficient justification to conclude that KSeF fundamentally alters self‑invoicing mechanisms or conditions the right to deduct VAT on additional technical criteria. Such an approach should be reconsidered in favour of one that respects VAT neutrality, legal certainty, and the original purpose of KSeF.

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

See also

Join the Linkedin Group on Global E-Invoicing/E-Reporting/SAF-T Developments, click HERE
Join the LinkedIn Group on ”VAT in the Digital Age” (VIDA), click HERE