What it means
The buyer name (BT-44) is the full name of the company or person you are invoicing. In UBL it is cbc:RegistrationName inside the buyer's cac:PartyLegalEntity, under cac:AccountingCustomerParty. The rule counts those elements and allows one.
Why it matters
EN 16931 allows at most one buyer name per invoice or credit note.
How to fix it
Open the customer record in your invoicing software and check that only one name is set, with no second name exported as the buyer name. To mention a department or an additional contact person, use the contact fields of the buyer instead. In the XML, keep one cbc:RegistrationName in cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity.
Once the file is corrected, check it again for free: Validate an invoice against EN 16931
Or fix the invoice in a form and download the corrected file, for 1 credit: Fix a rejected e-invoice
The rule as published
Buyer name shall occur maximum once Where this rule applies
| Rule set | Version |
|---|---|
| EN 16931 (UBL) | 1.3.17 |
| EN 16931 (UBL credit note) | 1.3.17 |
| XRechnung 3.0 (UBL) | 3.0.2 |
| XRechnung 3.0 (UBL credit note) | 3.0.2 |
| Peppol BIS Billing 3.0 (invoice) | 2026.5 |
| Peppol BIS Billing 3.0 (credit note) | 2026.5 |
| SI-UBL 2.0 / NLCIUS (invoice) | 2.0.3.13 |
| SI-UBL 2.0 / NLCIUS (credit note) | 2.0.3.13 |
| France CTC (UBL invoice) | 1.4.0-04 |
| France CTC (UBL credit note) | 1.4.0-04 |
| CIUS-RO UBL Invoice 1.0.9 | 1.0.9 |
| CIUS-RO UBL Credit Note 1.0.9 | 1.0.9 |
Check your file
Drop your e-invoice to see whether UBL-SR-15 still fails, and which other rules do.
Related rules
- UBL-SR-16 An invoice can have only one buyer identifier
- UBL-SR-17 An invoice can have only one buyer company registration number
- UBL-SR-18 An invoice can have only one buyer VAT number
- UBL-SR-19 The payee needs one name, different from the seller's
- UBL-SR-20 The payee can have one identifier and must differ from the seller
- UBL-SR-21 A separate payee needs a different name and at most one registration number