On August 27, 2025, Polish President Nawrocki signed the law regarding KSeF (National e-Invoicing System). The new regulations will enter into force on February 1, 2026, and will completely change how entrepreneurs document sales and issue invoices.
KSeF allows for the issuance and sharing of structured invoices.
The legislator has planned a gradual implementation:
• February 1, 2026 – for entrepreneurs whose sales value (including tax) exceeded PLN 200 million in 2024,
• April 1, 2026 – for all other entrepreneurs.
KSeF 2.0 System – open testing
As of September 1, 2025, the test version of the National e-Invoicing System (KSeF 1.0) was deactivated. In practice, this means that to become a new KSeF user, one must wait for the new KSeF 2.0 test environment.
On September 30, the Ministry of Finance will launch open testing for KSeF 2.0, which involves software testing to facilitate information exchange between the National e-Invoicing System and invoicing systems available on the market. This will allow financial-accounting software providers to check how their software integrates with the KSeF 2.0 system.
From October 15, users will be able to integrate via KSeF 2.0 with the pre-production environment (DEMO).
From February 1, 2026, the Ministry of Finance will launch the final version of the system, i.e., KSeF 2.0.
KSeF 2.0 Taxpayer Application
From November 1, the Certificates and Authorizations Module (MCU) will be activated, allowing users to assign authorizations. These will be necessary to use the National e-Invoicing System from February 1, 2026.
From November 3, 2025, users will be able to start testing the KSeF 2.0 Taxpayer Application in the test environment.