[BR-NG-03-GST-SG]-An Invoice that contains a Document level allowance (BG-20) where the Document level allowance GST category code (BT-95-GST) is "NG" shall not contain the Seller GST identifier (BT-31-GST), the Seller tax representative GST identifier (BT-63-GST) or the Buyer GST identifier (BT-48-GST).
BR-NG-03-GST-SG
/ubl:Invoice | /cn:CreditNote
(exists((/ubl:Invoice|/cn:CreditNote)/cac:AllowanceCharge[cbc:ChargeIndicator=false()]/cac:TaxCategory[normalize-space(cbc:ID) = 'NG'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='GST']) and (not(//cac:AccountingSupplierParty/cac:Party/cac:PartyTaxScheme[cac:TaxScheme/(normalize-space(upper-case(cbc:ID)) = 'GST')]/cbc:CompanyID) and not(//cac:TaxRepresentativeParty/cac:PartyTaxScheme[cac:TaxScheme/(normalize-space(upper-case(cbc:ID)) = 'GST')]/cbc:CompanyID) and not(//cac:AccountingCustomerParty/cac:Party/cac:PartyTaxScheme[cac:TaxScheme/(normalize-space(upper-case(cbc:ID)) = 'GST')]/cbc:CompanyID))) or not(exists((/ubl:Invoice|/cn:CreditNote)/cac:AllowanceCharge[cbc:ChargeIndicator=false()]/cac:TaxCategory[normalize-space(cbc:ID) = 'NG'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='GST']))