BR-NG-09-GST-SG
The GST category tax amount (BT-117-GST) in a GST breakdown (BG-23) where the GST category code (BT-118-GST) is "NG" shall be 0 (zero).
error: the document is invalid
What the rule checks
As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.
Context
cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory[normalize-space(cbc:ID) = 'NG'][cac:TaxScheme/normalize-space(upper-case(cbc:ID))='GST']
Test
../cbc:TaxAmount = 0
Checked with PINT SG Invoice, PINT SG Credit Note