What the integration covers
- FA(3) format: invoices and corrections are generated and submitted in the format KSeF requires.
- Durable queue: submissions go through a queue built to retry, so a temporary KSeF outage does not lose a document.
- KSeF number: lands on the document once the system accepts it.
- Official confirmation (UPO): downloadable once issued.
- Verification QR code: printed on the PDF, so a paper copy can still be checked against KSeF.
Why it sits in the core, not a plugin
KSeF submissions run on the same Redis-backed queue as webhooks and email delivery, with retries and a failed-jobs view in the admin panel. That is a platform capability, not a third-party extension bolted on after the fact.
KSeF landed in the July 2026 update, the same month as the Comarch ERP Optima and Subiekt GT connectors.