Free, open-source tools for KSeF, Poland's mandatory e-invoicing system. Check an invoice before you send it, find the right NBP exchange rate, and learn the rules in plain language. No accounting software needed.
The validator runs in your browser. Your invoice file never leaves it.
| Repository | What it is |
|---|---|
| ksefuj | The ksefuj.to website (validator, NBP rates, guides, blog, docs, FAQ) and @ksefuj/validator: the same FA(3) schema and Ministry of Finance rule checks as an npm package and the ksef-validate CLI |
| skills | Claude skills that generate FA(3) invoice XML and corrective invoices |
| awesome-ksef | A curated list of KSeF tools and resources |
Darmowe narzędzia do KSeF. Sprawdzisz fakturę, zanim ją wyślesz, znajdziesz kurs NBP do faktury w walucie i przeczytasz poradniki pisane ludzkim językiem. Walidator działa w przeglądarce, więc Twój plik jej nie opuszcza. Bez zakładania konta i bez limitów.
Free forever, no sign-up, no usage limits. Apache 2.0.