[BR-G-04]-An Invoice that contains a Document level charge (BG-21) where the Document level charge VAT category code (BT-102) is "Export outside the EU" shall contain the Seller VAT Identifier (BT-31) or the Seller tax representative VAT identifier (BT-63).
Stored validation assertion
(//ram:SellerTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID = 'VA'] or //ram:SellerTaxRepresentativeTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID = 'VA'])