Validation rules

UBL-SR-04

The invoiced-object identifier (BT-18) appears more than once — only one cac:AdditionalDocumentReference with DocumentTypeCode 130 is allowed.

Rule: UBL-SR-04 — 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 invoiced-object identifier (BT-18); BG-24 attachments are emitted without DocumentTypeCode 130/50.

How to fix it

Keep a single AdditionalDocumentReference with cbc:DocumentTypeCode 130; move other attachments to references without a type code.

UBL-SR-04 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil die Objektkennung (BT-18) mehrfach vorkommt — nur ein cac:AdditionalDocumentReference mit DocumentTypeCode 130 ist erlaubt.

So beheben Sie den Fehler

Behalten Sie genau eine AdditionalDocumentReference mit cbc:DocumentTypeCode 130; weitere Referenzen dürfen keinen Typcode tragen.

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.