BR-06
A rule of the European standard EN 16931 – applies to every invoice following the standard, including Peppol BIS Billing 3.0.
What this error means
BR-06
The seller name is missing (BT-27).
How to fix it
Fill in the seller's registered name: cac:AccountingSupplierParty → cac:PartyLegalEntity → cbc:RegistrationName.