BR-CO-04: Each Invoice line (BG-25) shall be categorized with an Invoiced item VAT category code…

This is a fatal XRechnung rule. It requires each invoice line (cac:InvoiceLine or cac:CreditNoteLine, described as BG-25) to be categorized with an Invoiced item VAT category code (BT-151). In UBL, the line must contain cac:Item/cac:ClassifiedTaxCategory where cac:TaxScheme/cbc:ID is VAT (case- and whitespace-insensitive) and that category must have a cbc:ID. A document fails when no such VAT-scheme category with a cbc:ID exists on a line. The CII equivalent uses ram:SpecifiedLineTradeSettlement/ram:ApplicableTradeTax with ram:TypeCode equal to VAT and a ram:CategoryCode.

In UBL, for each cac:InvoiceLine or cac:CreditNoteLine, add or correct cac:Item/cac:ClassifiedTaxCategory so that cac:TaxScheme/cbc:ID equals VAT and include cbc:ID with the applicable VAT category code. In CII, add or correct ram:SpecifiedLineTradeSettlement/ram:ApplicableTradeTax with ram:TypeCode equal to VAT and include ram:CategoryCode. Use the VAT category code that applies to the line; if the source system does not provide one, check the accepted VAT category code list for XRechnung.