What it means
The rule checks the seller's legal entity block (cac:PartyLegalEntity) and fails when it holds a cac:HeadOfficeParty, a full description of a head office with its own name, identifiers and address. EN 16931 describes one seller (BG-4) and has no field for a separate head office.
Why it matters
This is only a warning, so the invoice is still accepted. The recipient treats the seller block as the company that issued the invoice and does not read a head office inside it. Any VAT number or address that appears only in the head office block is not used.
How to fix it
Remove cac:HeadOfficeParty from cac:AccountingSupplierParty/cac:Party/cac:PartyLegalEntity. Then check that the ordinary seller fields, the name, the VAT number (BT-31) and the postal address (BG-5), belong to the company that issues the invoice. If your software has a head office or parent company setting, switch off its export. It is worth fixing when details exist only in the head office block, because the recipient will not see them.
The rule as published
A UBL invoice should not include the AccountingSupplierParty Party PartyLegalEntity HeadOfficeParty 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-CR-187 still fails, and which other rules do.