What’s KSeF and how do I prepare Magento for the 2026 mandate?

KSeF (Krajowy System e-Faktur) is the Polish Ministry of Finance’s mandatory e-invoicing platform. Originally planned for 2024, the mandate was rescheduled and is currently phased for 2026:

• From 1 Feb 2026, large Polish VAT payers (turnover > PLN 200M) must issue all B2B invoices via KSeF.
• From 1 April 2026, all other VAT-registered Polish businesses must issue e-invoices via KSeF.
• B2C invoices remain optional in KSeF (but allowed).

The format is FA(2) XML, structured XML schema published by Ministerstwo Finansów. Magento integration:

1. Generate a KSeF-compatible XML at order/invoice creation (FA(2) schema, UTF-8, signed).
2. Authenticate to KSeF via the API (token-based, certificate-signed).
3. POST the XML to KSeF’s endpoint; receive the assigned KSeF number (Numer KSeF).
4. Store the Numer KSeF on the Magento invoice; reference it on receipt PDFs.
5. Allow buyer-side retrieval from KSeF (B2B buyer can pull your invoice from KSeF).

We integrate via certified Polish PDPs / e-invoicing platforms (Comarch, Symfonia, inFakt, Asseco), Magento → PDP → KSeF. Or direct via the official API for high-volume stores.