On June 30, 2025, the Polish Ministry of Finance officially published the KSeF 2.0 API documentation along with the logical structure of the new FA(3) e-invoice schema. The technical materials include detailed specifications, changes from KSeF 1.0 to 2.0, and guidance for integration. Developed with input from experts and users, the FA(3) schema will fully replace the current FA(2) format starting February 1, 2026, when KSeF 2.0 becomes mandatory.
Implementation Timeline:
- June 30, 2025 – Publication of KSeF 2.0 API and FA(3) schema
- September 30, 2025 – KSeF 2.0 API test environment opens for integrators and enterprises
- November 2025 – Test version of the KSeF 2.0 Taxpayer Application becomes available
- February 1, 2026 – KSeF 2.0 and FA(3) become mandatory for large taxpayers
- April 2026 to January 2027 – Gradual rollout for SMEs and micro-businesses
Regulations supporting KSeF 2.0 are expected to be finalized by July 2025. Businesses and software providers are strongly encouraged to begin preparations using the official resources available on the KSeF portal.
