Validation rules

UBL-SR-15 — UBL rule

The buyer name (BT-44) appears more than once — the customer party may carry only one PartyLegalEntity/RegistrationName.

Rule: UBL-SR-15 — official EN 16931 / XRechnung rule
Severity: error
Business term: BT-44 — Buyer name
Field in your JSON: invoice.buyer.name
Detected by: tier 3 — KoSIT validator (authoritative)
Reachability: Only reachable when validating your own XML — normbill-generated documents cannot trigger it

The serializer writes invoice.buyer.name as exactly one RegistrationName.

How to fix it

Keep a single cac:PartyLegalEntity/cbc:RegistrationName under cac:AccountingCustomerParty.

UBL-SR-15 auf Deutsch — was bedeutet der Fehler?

Der KoSIT-Validator lehnt die Rechnung ab, weil der Käufername (BT-44) mehrfach vorkommt — die Käuferpartei darf nur einen PartyLegalEntity/RegistrationName tragen.

So beheben Sie den Fehler

Behalten Sie genau einen cac:PartyLegalEntity/cbc:RegistrationName unter cac:AccountingCustomerParty.

Related rules

BR-07 — The buyer name (BT-44) is missing or empty.
UBL-SR-14 — The seller's additional legal information (BT-33) appears more than once — only one…
UBL-SR-16 — The buyer identifier (BT-46) appears more than once — the customer party may carry only one…
UBL-SR-13 — The seller tax registration identifier (BT-32) appears more than once — only one non-VAT PartyTaxScheme may…
UBL-SR-17 — The buyer legal registration identifier (BT-47) appears more than once — only one PartyLegalEntity/CompanyID…
UBL-SR-12 — The seller VAT identifier (BT-31) appears more than once — only one PartyTaxScheme with TaxScheme/ID 'VAT'…

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.