[BR-O-01]-An Invoice that contains an Invoice line (BG-25), a Document level allowance (BG-20) or a Document level charge (BG-21) where the VAT category code (BT-151, BT-95 or BT-102) is "Not subject to VAT" shall contain exactly one VAT breakdown group (BG-23) with the VAT category code (BT-118) equal to "Not subject to VAT".
Stored validation assertion
not(//ram:ApplicableHeaderTradeSettlement/ram:ApplicableTradeTax[ram:CategoryCode='O']) or ( count(//ram:ApplicableHeaderTradeSettlement/ram:ApplicableTradeTax[ram:CategoryCode='O'])=1 and (exists(//ram:SpecifiedLineTradeSettlement/ram:ApplicableTradeTax[ram:CategoryCode='O']) or exists(//ram:CategoryTradeTax[ram:CategoryCode='O'])))