Validation rules
BR-55
A preceding-invoice reference (BG-3) is present but the preceding invoice number (BT-25) is missing.
- Rule
BR-55— official EN 16931 / XRechnung rule- Severity
- error
- Business term
BT-25— Preceding invoice number- Field in your JSON
invoice.preceding_invoice- Detected by
- tier 3 — KoSIT validator (authoritative)
- Reachability
- Only reachable when validating your own XML — normbill-generated documents cannot trigger it
The serializer only writes cac:BillingReference when invoice.preceding_invoice is set (non-empty).
How to fix it
Add cac:InvoiceDocumentReference/cbc:ID to the cac:BillingReference.
BR-55 auf Deutsch — was bedeutet der Fehler?
Eine Referenz auf eine Vorgängerrechnung (BG-3) ist vorhanden, aber die Nummer der Vorgängerrechnung (BT-25) fehlt.
So beheben Sie den Fehler
Ergänzen Sie cac:InvoiceDocumentReference/cbc:ID in der cac:BillingReference.
Official sources
- XRechnung specification (KoSIT / xeinkauf.de)
- KoSIT validator on GitHub and the XRechnung validator configuration
Every 422 from the API lists the rule id, the path in your request JSON, a plain-language message and a suggested fix — see the docs overview for the report format.
Or try it live: drop any XRechnung XML on the free validator — same KoSIT-backed report, no account.