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 "IPSI" shall contain in the VAT breakdown (BG-23) at least one VAT category code (BT-118) equal with "IPSI".
/ubl:Invoice | /cn:CreditNote((count(//cac:AllowanceCharge/cac:TaxCategory[normalize-space(cbc:ID) = 'M'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']) + count(//cac:ClassifiedTaxCategory[normalize-space(cbc:ID) = 'M'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT'])) > 0 and count(cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory[cbc:ID = 'M'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']) > 0) or ((count(//cac:AllowanceCharge/cac:TaxCategory[normalize-space(cbc:ID) = 'M'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']) + count(//cac:ClassifiedTaxCategory[normalize-space(cbc:ID) = 'M'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT'])) = 0 and count(cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory[normalize-space(cbc:ID) = 'M'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']) = 0)