BR-CO-26: The seller carries no identifying number
This code shows up when an electronic invoice is validated. Here is what it means, why it fires, and what to change in the file.
Why this code appears
The seller carries no legal registration identifier (BT-30), no VAT identifier (BT-31) and no seller identifier (BT-29). None of the three is mandatory on its own, but one of them is: without it, nobody can tie the invoice to a real company.
How to fix it
Add at least the legal registration number in SpecifiedLegalOrganization/ID with its schemeID, or the VAT number in SpecifiedTaxRegistration/ID with schemeID="VA".
Where it happens
This code comes from EN 16931, the European e-invoicing standard. It concerns business term BT-30.