[BR-48-GST-SG]-Each GST breakdown (BG-23-GST) shall have a GST category rate (BT-119-GST), except if the Invoice is not subject to GST.
BR-48-GST-SG
cac:TaxTotal/cac:TaxSubtotal
exists(cac:TaxCategory[cac:TaxScheme/cbc:ID='GST']/cbc:Percent) or exists(normalize-space(cac:TaxCategory[cac:TaxScheme/cbc:ID='GST']/cbc:ID)='NG')