Poland’s national e-invoicing system (KSeF) – a summary of the first days of operation

The first days of the system showed significant technical problems that made it difficult for taxpayers to meet their obligations. In particular, there were login issues caused by system overload and problems with the Trusted Profile, which is the main method of user authentication. As a result, taxpayers could not access the system, or received multiple errors. These issues were partly resolved by introducing alternative authentication methods, such as the mObywatel app and qualified electronic signatures.

Further problems included so-called “teething issues”, such as invoices not being properly transferred between the issuer and the recipient, as well as errors in the data, including VAT rates.

In practice, KSeF currently works mainly as a system for approving invoices rather than creating them. Most invoices are prepared in commercial accounting systems and then sent to KSeF via application programming interface (API) integration. This is because the government system does not store key data, such as customer details or bank accounts, which must be entered manually each time. This is especially problematic for companies issuing a large number of invoices, such as in trade or e-commerce.

For this reason, most taxpayers continue to use commercial systems integrated with KSeF, although not all businesses have completed the implementation process. In response to these challenges, a social movement called “KSeF to the trash” has emerged, pointing out possible violations of business freedom and the risk of disrupting operations, especially for small businesses. A draft law to postpone the obligation was also submitted, but it was not adopted.

There are also concerns about the right to deduct VAT from invoices issued outside KSeF by entities that are required to use it. However, the current position of the Krajowa Informacja Skarbowa (the specialised body within the National Tax Administration, KAS, that provides uniform tax and customs information) confirms that the lack of an invoice in KSeF does not remove the right to deduct input VAT. This was confirmed by an individual ruling dated 10 March 2026 (No. 0114-KDIP4-1.4012.33.2026.1.S). The same approach applies to income tax, which is favourable for taxpayers.

It should also be noted that no penalties will be imposed in 2026 for failing to comply with KSeF obligations. Penalties will be introduced from 2027, and may reach up to 100% of the VAT amount, or 18.7% of the total amount due for VAT-exempt taxpayers.

In summary, KSeF creates significant uncertainty for taxpayers. However, with the lack of penalties in 2026, its mandatory nature currently has more of an instructional than a punitive character.

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Anita Tulak is a graduate of the Faculty of Law and Administration and a tax advisor at the National Chamber of Tax Advisors. She has passed through all levels of career in accounting and tax law, from assistant to partner of a law firm and worked for recognised private consulting firms and the “Big Four” company PwC.