Documentation
KSeF Kit documentation
How to connect Stripe, link KSeF, and file invoices. Short and to the point.
- Quick start Install the app, finish the 3-step onboarding, file your first test invoice.
- How filing works From a Stripe invoice through FA(3) and a KSeF session to the UPO and write-back.
- Selling worldwide Which of your sales become KSeF invoices and which don't — PL, EU and non-EU, business and consumer.
- Connecting KSeF Token vs XAdES, TEST first, test the connection, switch to PROD deliberately.
- Going live (TEST → PRODUCTION) From a test filing to a real one: the readiness checklist and one deliberate switch to PROD.
- Corrections (KOR) A Stripe credit note filed as an FA(3) KOR referencing the original KSeF number.
- Currency & NBP Non-PLN invoices converted at the NBP average rate of the last business day before issue.
- Plans & billing Free tier of 15 filings per rolling month, Pro and Business tiers, billing.
- Data & security What we store, how tokens are encrypted, and why the TEST environment is completely safe.
- Self-hosting The restricted-API-key edition — run KSeF Kit on your own server.
- Rejections & troubleshooting The most common KSeF rejection codes translated into a plain-language fix.