XRechnung 2.4.0 · UBL
Rules: XRechnung Schematron rules by Koordinierungsstelle für IT-Standards (KoSIT) · Apache-2.0
[BR-O-09]-The VAT category tax amount (BT-117) in a VAT breakdown (BG-23) where the VAT category code (BT-118) is "Not subject to VAT" shall be 0 (zero).
xs:decimal(../cbc:TaxAmount) = 0