KSeF software: how to choose a tool that keeps you compliant

As KSeF becomes mandatory, every Polish accounting and invoicing tool is adding a "KSeF" label. Here's how to judge whether one actually keeps you compliant — the same discipline as choosing any e-invoicing software, tuned to Poland.

1. Real KSeF submission (not just an FA_VAT export)

The tool must submit to KSeF and return the KSeF number and UPO — not merely generate an XML file you then upload elsewhere. Ask to see the confirmation flow.

2. Authentication that fits automation

Check how it authenticates: token, trusted profile, or qualified signature/seal. For hands-off invoicing you want a token-based flow that doesn't need a human every time — with sensible permission management.

3. Valid, current FA_VAT

It must build schema-valid FA_VAT and keep up as the schema evolves (FA(2) → FA(3)). Ask how they handle format updates — this is ongoing, not one-off.

4. Receiving, not just sending

You also receive through KSeF. The tool should pull invoices addressed to your NIP and reconcile them into your books.

5. UPO storage and audit

Every issued invoice needs its KSeF number + UPO + submitted XML retained. Confirm the tool stores these and lets you retrieve them for audit.

6. Corrections done right

Corrections are correcting invoices through KSeF — the tool must support them natively, not by editing the original.

7. Test environment support

Good software lets you validate against the test/demo environment before going live. Avoid tools that only touch production.

8. Cross-border, if you need it

KSeF is domestic. If you also trade across the EU, either the tool covers Peppol/EN 16931 too, or you pair it with an EU e-invoicing tool. Don't discover the gap after go-live.

The checklist

□ Submits to KSeF; returns KSeF number + UPO
□ Token / signature / trusted-profile auth
□ Valid, up-to-date FA_VAT (FA(2)→FA(3))
□ Receives + reconciles invoices by NIP
□ Stores KSeF number, UPO, XML for audit
□ Native correcting invoices
□ Test/demo environment support
□ A plan for cross-border (Peppol/EU)

Where Eurobillr fits

Eurobillr is the cross-border/EU half of that checklist — Peppol/EN 16931 send and receive (Belgium, France via an accredited platform, Italy, Germany), VAT handling and multi-currency — for Polish businesses that also invoice abroad. Domestic KSeF submission is Poland's national system; you'd use a KSeF-connected tool or KSeF directly for that. Trading both domestically and across the EU? Eurobillr keeps the EU side compliant while you run KSeF for Poland.

Related: how to choose Peppol software · KSeF API.