E-Invoicing in Poland
KSeF clearance mandate, phased February and April 2026, national FA XML schema
The mandate at a glance
Poland operates a clearance model: every domestic invoice must be issued through KSeF (Krajowy System e-Faktur), the national e-invoicing platform, which validates the document and assigns it an official identifier before it reaches the buyer. An invoice that never went through KSeF is not a valid invoice for domestic B2B in Poland.
The mandate arrived in two waves in 2026: large taxpayers in February, everyone else in April. This makes Poland, alongside Italy, one of the two big EU markets where integrating with a government platform, not just producing a compliant file, is the core engineering task.
| Date | Obligation | Scope |
|---|---|---|
| February 1, 2026 | Issue invoices through KSeF | Large taxpayers (turnover above PLN 200 million) |
| April 1, 2026 | Issue invoices through KSeF | All remaining VAT-registered businesses |
Required formats and network
Required format: Poland's national structured XML schema (the FA schema), submitted to KSeF. It is not an EN 16931 syntax: EN 16931-compliant CII or UBL documents must be mapped to the KSeF schema for submission. For cross-border invoices and EU trading partners, EN 16931 formats remain the practical interchange layer, with the KSeF submission generated from the same data.
How to comply
- Integrate with the KSeF API (or a provider that wraps it) for issuing and receiving.
- Map your canonical invoice data model to the national FA schema.
- Store the KSeF identifier returned at clearance with every invoice record.
- Keep an EN 16931 pipeline (CII/UBL) for cross-border invoices, which follow separate rules.
What InvoiceXML supports for Poland
Frequently asked questions
What is KSeF?
KSeF (Krajowy System e-Faktur) is Poland's national e-invoicing clearance platform. Invoices are submitted to KSeF, validated, assigned an official KSeF number, and made available to the buyer. Issuing through KSeF is what makes the invoice legally valid.
Does Poland accept EN 16931 formats like UBL or CII?
Not for domestic KSeF submission: the platform requires Poland's national FA XML schema. EN 16931 data maps onto it, so most integrations keep a canonical EN 16931 pipeline and generate the KSeF payload from it.
When did KSeF become mandatory?
February 1, 2026 for large taxpayers with turnover above PLN 200 million, and April 1, 2026 for all other VAT-registered businesses.
Do cross-border invoices go through KSeF?
Invoices to foreign businesses without a Polish establishment follow separate rules and are typically exchanged in EN 16931 formats, while the domestic leg of reporting is handled via KSeF. Verify the current scope for your exact scenario.
E-Invoicing in Germany →
E-Invoicing in Romania →
E-Invoicing in Italy →