Validation rules

UBL-SR-08

The invoicing period (BG-14) appears more than once — only one document-level cac:InvoicePeriod is allowed.

Rule: UBL-SR-08 — 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 serializer emits at most one document-level InvoicePeriod, from invoice.invoicing_period.

How to fix it

Keep a single cac:InvoicePeriod at document level; per-line periods belong inside the invoice lines (BG-26).

UBL-SR-08 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil der Abrechnungszeitraum (BG-14) mehrfach vorkommt — nur ein cac:InvoicePeriod auf Dokumentebene ist erlaubt.

So beheben Sie den Fehler

Behalten Sie genau eine cac:InvoicePeriod auf Dokumentebene; Zeiträume je Position gehören in die Rechnungsposition (BG-26).

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.