Validation rules

UBL-SR-23

The tax representative VAT identifier (BT-63) appears more than once — only one PartyTaxScheme/CompanyID is allowed in the tax representative party.

Rule: UBL-SR-23 — 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 representative (BG-11); generated XML never contains cac:TaxRepresentativeParty.

How to fix it

Keep a single CompanyID inside the tax representative's PartyTaxScheme.

UBL-SR-23 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil die USt-IdNr. des Steuervertreters (BT-63) mehrfach vorkommt — nur eine PartyTaxScheme/CompanyID ist erlaubt.

So beheben Sie den Fehler

Behalten Sie genau eine CompanyID im PartyTaxScheme des Steuervertreters.

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.