Poland e-invoicing mandate: KSeF from 2026

Poland's mandatory B2B e-invoicing via the central KSeF system: large taxpayers from February 2026, others from April 2026. Clearance model, structured XML.

Large taxpayers (2024 turnover > PLN 200m) from 1 February 2026
All other VAT-registered businesses from 1 April 2026
Micro-entrepreneurs (monthly turnover <= PLN 10,000) from 1 January 2027
Model Central clearance via KSeF (structured XML)

Poland is introducing mandatory B2B e-invoicing through the national KSeF system (Krajowy System e-Faktur) — a central clearance model that handles both B2B and B2G invoices.

Timeline

The start is phased by turnover: large taxpayers with 2024 turnover above PLN 200m from 1 February 2026, all other VAT-registered businesses from 1 April 2026, and micro-entrepreneurs with monthly turnover up to PLN 10,000 from 1 January 2027. All B2B invoices must be validated by KSeF as structured XML before they carry legal force.

Format and model

KSeF uses a national structured XML schema (FA(3)) and, like Italy's SdI, operates as a clearance platform: the tax administration sits in the invoice flow. By 2035 Poland must align its system with the ViDA rules and EN 16931.

How invowerk helps

invowerk validates the EN-16931 fields of an invoice and explains error codes in plain language (see /codes). Submission in Poland must go through KSeF; the upstream format and field checks plus UBL/CII conversion are handled by the API.