Numer KSeF
On this page
Invoice identifier assigned by Poland's KSeF.
Definition
The Numer KSeF is generated by the Ministry of Finance central system the moment an invoice (e-Faktura in the FA XSD schema) passes the controls and is registered. It acts as the invoice's official reference, is required for split-payment (MPP) transfers, and appears inside the UPO confirmation. It does not replace the commercial invoice number chosen by the seller.
Origin
Defined in the Krajowy System e-Faktur documentation published by the Ministerstwo Finansów / Krajowa Administracja Skarbowa on podatki.gov.pl, under the VAT Act (Ustawa o VAT).
Example in context
Numer KSeF: 1111111111-20260620-A1B2C3D4E5F6-7A (NIP-date-hash-checksum).