- KSeF 1.0 production environment can be used until 26 January 2026.
- A technical maintenance break will occur from 26-31 January 2026 for KSeF 1.0.
- KSeF 2.0 production environment goes live on 1 February 2026, coinciding with the start of mandatory e-invoicing for large taxpayers.
- All taxpayers in scope must be ready to use and receive invoices via KSeF 2.0 from 1 February 2026.
- KSeF 2.0 test and demo environments are not expected to be affected during this transition.
Source: sovos.com
Note that this post was (partially) written with the help of AI. It is always useful to review the original source material, and where needed to obtain (local) advice from a specialist.
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