Validation rules

UBL-SR-49

The tax point date code (BT-8) appears more than once — only one cac:InvoicePeriod/cbc:DescriptionCode is allowed.

Rule: UBL-SR-49 — 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 tax point date code; generated XML never contains cac:InvoicePeriod.

How to fix it

Keep a single DescriptionCode inside the document-level InvoicePeriod.

UBL-SR-49 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil der Code des Steuer-Stichtags (BT-8) mehrfach vorkommt — nur ein cac:InvoicePeriod/cbc:DescriptionCode ist erlaubt.

So beheben Sie den Fehler

Behalten Sie genau einen DescriptionCode in der dokumentweiten InvoicePeriod.

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.