National e-Invoicing System (KSeF) in Poland - Implementation Timeline and Key Developments

The process of implementing the National e-Invoicing System proved to be much more complex than originally anticipated, leading to a postponement of its mandatory use. The delay was due, among other things, to the need to refine technical issues and ensure greater stability of the system.

According to the current deadlines, as of February 1, 2026, the obligation will apply to large entities (whose sales value for 2024, including the amount of tax, exceeded PLN 200 million), while as of 
April 1, 2026, it will apply to other entrepreneurs, with the exception of the smallest “digitally excluded” taxpayers, whose transactions involve small amounts (up to a total sales value of up to PLN 10,000 per month) and who will be subject to the obligation as of January 1, 2027.

In response to numerous questions and unspecified issues regarding the entire process of introducing structured invoices, the Finance Ministry has presented an updated timetable for implementing the system. Its new version - KSeF 2.0  is expected to enable taxpayers to make a smooth transition to the mandatory e-invoicing model. At the end of May 2025, an updated draft law introducing the system was published, as well as a draft of the so-called technical regulation and the KSeF exemption regulation. Below we present a plan of the most important technical adjustments and a summary of the proposed initiatives and solutions being implemented in Poland.

• June 2025 - Release of the new FA(3) structured invoice logical structure template and software interface (API) documentation,
• July 2025 - Anticipated completion of the legislative process,
• September 2025 - Possibility of open testing of the KSeF 2.0 programming interface (API) by all integrators and large companies,
• November 2025 - provision of invoice issuer certificates, opportunity to use free trial version of KSeF 2.0 Taxpayer Application, 
• February 2026 - release of the production version of the system, allowing the issuance of invoices in real business.

New initiatives and changes among others include:

• “Offline24” mode - the possibility of issuing an e-invoice outside the system without additional restrictions (the previous version of the draft assumed the possibility of using only for network problems, among other things), with subsequent integration with KSeF,
• Consumer invoices and invoice sharing - the possibility of sharing invoices outside KSeF (in an agreed manner) will apply to consumers and entities without a VAT number, among others,
• Invoice issuer certificates - available from November 2025, their introduction will allow authentication in the system and is necessary for issuing e-invoices in case of system failure and in “offline24” mode,
• Verification codes - changes include including a verification code (e.g., QR code or link) on the invoice visualization or uploading as a separate document, which will immediately identify the invoice in the system, 
• VAT RR invoices - postponing the possibility of issuing them in the system to April 1, 2026,
• Limitation of penalties - no penalties for e-invoicing errors until the end of 2026,
• The KSeF 2.0 Taxpayer Application - in a test version will be available from November 2025.

The legal framework outlined above reflects the current stage of the legislative process. Given its evolving nature, we recommend closely monitoring further updates, solutions and clarifications announced by the Ministry of Finance.