FX-SCH-A-000099
An Invoice that contains a Document level charge (BG-21) where the Document level charge VAT category code (BT-102) is "Reverse charge" shall contain the Seller VAT Identifier (BT-31), the Seller tax registration identifier (BT-32) and/or the Seller tax representative VAT identifier (BT-63) and the Buyer VAT identifier (BT-48) and/or the Buyer legal registration identifier (BT-47).
What the rule checks
As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.
[BR-AE-04] An Invoice that contains a Document level charge (BG-21) where the Document level charge VAT category code (BT-102) is "Reverse charge" shall contain the Seller VAT Identifier (BT-31), the Seller tax registration identifier (BT-32) and/or the Seller tax representative VAT identifier (BT-63) and the Buyer VAT identifier (BT-48) and/or the Buyer legal registration identifier (BT-47).
//ram:SpecifiedTradeAllowanceCharge[ram:ChargeIndicator/udt:Indicator='true']/ram:CategoryTradeTax[ram:CategoryCode = 'AE'](//ram:SellerTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID = ('VA', 'FC')] or //ram:SellerTaxRepresentativeTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID = 'VA']) and (//ram:BuyerTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID = 'VA'] or //ram:BuyerTradeParty/ram:SpecifiedLegalOrganization/ram:ID)Checked with Factur-X / ZUGFeRD BASIC