- The Ministry of Finance launched the Certificate and Authorization Module (MCU) in the National e-Invoice System (KSeF) on November 1, 2025.
- MCU allows users to manage authorizations, apply for, and download certificates needed to use KSeF; issuing new authorizations is now only possible via MCU, not the previous KSeF 1.0 application.
- Certificates confirm identity and enable issuing and receiving invoices on behalf of a company; they must be protected and not shared with unauthorized persons.
- Users are warned to treat certificates and MCU login data as highly sensitive, similar to banking credentials, to prevent fraud and unauthorized access.
- From February 1, 2026, only certificates and authorizations issued via MCU will be legally valid for KSeF 2.0.
Source: gov.pl
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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