/ubl:Invoice/cac:TaxTotal[cbc:TaxAmount/@currencyID = ../cbc:DocumentCurrencyCode]/cbc:TaxAmount/@currencyID

VRBL-Invoice-PT-2p1 - Invoice Tax Amount Currency Code

Portugal | VRBL-Invoice-PT-2p1

Context ID	INV1035
Usage	M

Description

Syntax required attribute, value must equal invoice document currency (IBT-005).