KSeF
KSeF number in the ledger: what is it?
The number identifying an invoice in the National e-Invoice System, entered in KPiR and the register
From 2026, in KPiR (column 3) and in the revenue register you enter the number under which the invoice is held in KSeF. Another accounting document has a separate column.
Key answers
- What it is
- The number identifying an invoice in KSeF, entered in the ledger if the invoice was issued through KSeF. In KPiR it is column 3, and column 4 is for another accounting document number. The KSeF number of an invoice for the sale of a fixed asset also goes to the fixed-asset and intangible register.
- Who it affects
- Taxpayers keeping KPiR and a revenue register who have structured invoices from KSeF.
- When
- When entering the invoice. With the cash method (art. 14c of the PIT Act) you enter the designation of the invoice documenting the revenue that arises on the date set in art. 14c(2).
- Where
- Column 3 of KPiR (Dz.U. 2025 item 1299) and the matching column of the revenue register (Dz.U. 2025 item 1294), in the layouts in force from 1 January 2026.
How it works in Zaksio
Zaksio enters the KSeF number in the ledger automatically from an invoice downloaded from KSeF or issued in the program.
This is information, not legal advice. As of 2026-10. Deadlines and rules may change, so check them in the official source.
