Validation rules

UBL-SR-23 — UBL rule

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.

Related rules

UBL-SR-22 — The tax representative name (BT-62) appears more than once — cac:TaxRepresentativeParty may carry only one…
UBL-SR-24 — Delivery information (BG-13) appears more than once — only one cac:Delivery element is allowed.
UBL-SR-21 — The payee legal registration identifier (BT-61) is invalid: at most one PartyLegalEntity/CompanyID is…
UBL-SR-25 — The deliver-to party name (BT-70) appears more than once — cac:Delivery may carry only one…
UBL-SR-20 — The payee identifier (BT-60) is invalid: cac:PayeeParty may carry at most one PartyIdentification/ID (SEPA…
UBL-SR-26 — The payment reference (BT-83) appears more than once in a cac:PaymentMeans — only one cbc:PaymentID per…

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.