As of 1 February 2026, VAT businesses need to be ready to receive invoices via KSeF and for some of them that date will mark the time when they will have to start issuing their invoices in KSeF as well. There is not much time left to make decisions and start the implementation process, considering that, after a few months’ pause, the Finance Ministry have now resumed consistently pursuing their KSeF implementation agenda.

In June the Ministry published three extremely important documents:

  • Legislative Package – a full set of government-initiated legislation proposals adopted by the Cabinet on 12 June to make obligatory KSeF a law. The relevant bill was transmitted to the Sejm on 25 June and had its first reading during the parliamentary sitting on 9 July.
  • FA(3) Logical Schema – 25 June saw the publication of the final version of the e-invoice schema to replace the current FA(2) schema as of 1 February 2026.
  • KSeF 2.0 API Documentation – the documentation, which was provided on 30 June, contains technical details, method descriptions, data structures, parameters and numerous examples to be used when building an interface between KSeF and the particular IT solutions adopted by businesses.

The Ministry’s KSeF 2.0 implementation schedule for the nearest months is as follows:

  • July 2025 – legislative processes completed.
  • 30 September 2025 – KSeF 2.0 API made available for open testing to all integrators and enterprises.
  • November 2025 – KSeF 2.0 Taxpayer Application made available, implementing the full set of functions supported by KSeF 2.0 API.
  • 1 February 2026 – system go-live in production environment, enabling businesses to issue structured invoices (1st stage of mandatory KSeF implementation).

Given that schedule, companies are now at a turning point when they need to decide on KSeF implementation method and scope. Successful KSeF implementation depends on a practical understanding of the system and the knowledge of current law and FM’s published documents. Importantly, KSeF implementation is not only about technical solutions but is also related to procedural changes in the organisation and in its entire document management process (both internal and external).

WTS&SAJA has extensive experience in KSeF implementation projects. What is more, we are able to support your implementation efforts internationally by customising solutions to align them with local regulations and market specifics.

If this issue pertains to your business and you are interested in our assistance, please contact us.

This blog post is provided for general information purposes to keep you up-to-date with changes in tax law, tax rulings by authorities, case law of courts and interesting commentaries. Doradztwo Podatkowe WTS&SAJA shall not be held legally liable for any acts or omissions resulting from reliance on such information.