Message

A Document level charge (BG-21) where the VAT category code (BT-102) is "Not subject to VAT" shall not contain a Document level charge VAT rate (BT-103).

Context
cac:AllowanceCharge[cbc:ChargeIndicator=true()]/cac:TaxCategory[normalize-space(cbc:ID)='O'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']
Test
not(cbc:Percent)
Usage
/ ubl:Invoice / cac:AllowanceCharge / cac:TaxCategory / cbc:Percent
/ ubl:CreditNote / cac:AllowanceCharge / cac:TaxCategory / cbc:Percent