UBL-CR-481: Do not put an exemption reason text on an invoice-level discount or charge

What it means

The rule looks at the discounts (BG-20) and charges (BG-21) placed on the whole invoice, directly under the invoice or credit note. It warns when the cac:TaxCategory inside one of them has a cbc:TaxExemptionReason. In EN 16931 the reason a supply is exempt from VAT is given once per category in the VAT breakdown (BG-23), as a reason text (BT-120) or a reason code (BT-121).

Why it matters

EN 16931 places VAT exemption reasons in the VAT breakdown (BG-23), not on document-level discounts (BG-20) or charges (BG-21).

How to fix it

Delete cbc:TaxExemptionReason from the cac:TaxCategory inside each cac:AllowanceCharge directly under the Invoice or CreditNote element. If an exemption reason is required for the VAT category, check that the matching row of the VAT breakdown (cac:TaxTotal, cac:TaxSubtotal, cac:TaxCategory) has the reason text or reason code. In your invoicing software this is the VAT exemption reason of the VAT category you used. Check the corrected file again.

The rule as published

A UBL invoice should not include the AllowanceCharge TaxCategory TaxExemptionReason

Where this rule applies