E-invoicing mandates
Poland KSeF: the 2026 e-invoicing deadlines explained
Poland's KSeF makes structured e-invoicing mandatory in 2026. Who must use it from February and April 2026, the grace period before penalties in 2027, how the central clearance platform works, and who is out of scope.
Last reviewed 2 June 2026
Poland's National e-Invoicing System (KSeF. Krajowy System e-Faktur) becomes mandatory in 2026, after several postponements. It is a centralised government platform: invoices are issued through KSeF, which validates and clears them in real time.
The timeline
The duty to issue through KSeF is phased by size, with a grace period before penalties begin.
| Date | Obligation |
|---|---|
| 1 Feb 2026 | Large taxpayers (prior-year turnover above PLN 200 million) must issue via KSeF. |
| 1 Apr 2026 | All other VAT taxpayers must issue via KSeF. |
| 1 Jan 2027 | The smallest taxpayers are brought in; penalties for non-compliance begin. |
How KSeF works
KSeF is a clearance model: rather than sending an invoice directly to your customer, you submit a structured XML invoice (the FA(3) schema) to the government platform, which validates it, assigns it an identifier and makes it available to the buyer. This is different from the Peppol model used in Belgium, where invoices travel between private Access Points.
Because the invoice is structured XML, a plain PDF is not a compliant KSeF invoice.
Who is in and out of scope
KSeF applies to domestic VAT taxpayers in Poland. Foreign businesses without a fixed establishment in Poland are generally outside the obligation to issue via KSeF.
Frequently asked questions
When is KSeF mandatory in Poland?
From 1 February 2026 for large taxpayers (prior-year turnover above PLN 200 million) and from 1 April 2026 for all other VAT taxpayers. The smallest micro-entrepreneurs follow in 2027. Penalties for non-compliance begin on 1 January 2027.
Can I send a PDF invoice under KSeF?
No. KSeF requires a structured XML invoice (the FA(3) schema) submitted to the central platform; a plain PDF is not a compliant KSeF e-invoice.
Does KSeF apply to foreign companies?
Foreign businesses without a fixed establishment in Poland are generally outside the obligation to issue via KSeF. Confirm your situation with a Polish tax adviser.
This guide is general information, not legal or tax advice. E-invoicing rules and dates change; always confirm the current position with the official source below or a qualified adviser before acting.
Invoicing a Polish client today?
euinvoice generates a compliant Polish invoice PDF with the right VAT and legal text, including reverse charge. Pro users can export Factur-X (EN 16931); KSeF-ready output is on our roadmap.