15 September 2025

KSeF 2.0 schedule for Test Environment

The Ministry of Finance has decided to shut down the test environment for the National e-Invoice System version 1.0 as of September 1st. This means that new users will only be able to use the KSeF environment in the new test environment, version 2.0.

Users of the current KSeF 1.0 production system can continue to use this option until the maintenance break, which the Ministry of Finance has announced for the period from January 26th to January 31, 2026.

Starting September 30th, the Ministry of Finance plans to launch open tests for the KSeF 2.0 API (i.e., tests of software for exchanging information between the KSeF 2.0 environment and external accounting systems for invoicing). This will allow for verification of the compatibility of external accounting modules with the KSeF 2.0 system.

Additionally, on October 15th, integration of the KSeF 2.0 API with the pre-production environment (DEMO) will be possible.

When will application testing be available?

Three dates are important for anyone interested in testing the KSeF 2.0 Taxpayer Application:

• November 1st – The Certificates and Authorizations Module will be launched on this date. (MCU), which will enable granting system access rights.
• November 3rd – enabling testing of the KSeF 2.0 Taxpayer Application in a test environment.
• November 15th – making the Application available in a pre-production environment.

KSeF schedule – important reminder

We remind you of the mandatory KSeF implementation dates:

• From February 1st, 2026, issuing structured invoices in KSeF will be mandatory for the largest taxpayers (sales value including VAT exceeding 200 million PLN).
• From April 1st, 2026, for other taxpayers.