What it means
The seller name (BT-27) is the full legal name of the company or person issuing the invoice. In UBL it is cbc:RegistrationName inside the seller's cac:PartyLegalEntity. The rule counts those elements and allows one.
Why it matters
EN 16931 allows at most one seller name per invoice or credit note.
How to fix it
Check the company name in the seller or company settings of your invoicing software and make sure only one name is set, with no second legal name or alias in a field that is exported as the seller name. If you also trade under another name, enter it as the trading name (BT-28) instead. In the XML, keep one cbc:RegistrationName in cac:AccountingSupplierParty/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
Seller 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-09 still fails, and which other rules do.
Related rules
- UBL-SR-10 An invoice can have only one seller trading name
- UBL-SR-11 An invoice can have only one seller company registration number
- UBL-SR-12 An invoice can have only one seller VAT number
- UBL-SR-13 An invoice can have only one seller tax number
- UBL-SR-14 Seller additional legal information can be given only once
- UBL-SR-15 An invoice can have only one buyer name