Validation rules

UBL-SR-17

The buyer legal registration identifier (BT-47) appears more than once — only one PartyLegalEntity/CompanyID is allowed.

Rule: UBL-SR-17 — official EN 16931 / XRechnung rule
Severity: error
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Only reachable when validating your own XML — normbill-generated documents cannot trigger it

The normbill invoice model has no buyer legal registration identifier; the serializer never emits this CompanyID.

How to fix it

Keep a single cbc:CompanyID inside the customer's cac:PartyLegalEntity.

UBL-SR-17 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil die Registernummer des Käufers (BT-47) mehrfach vorkommt — nur eine PartyLegalEntity/CompanyID ist erlaubt.

So beheben Sie den Fehler

Behalten Sie genau eine cbc:CompanyID in der cac:PartyLegalEntity des Käufers.

Official sources

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.