BR-KSA-80
The Pre-Paid amount (BT-113) must be equal to the sum total of the Prepayment VAT category Taxable Amount (KSA-31) and the Prepayment VAT Category Tax Amount (KSA-32).
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.
/ubl:Invoice | /cn:CreditNote
cac:LegalMonetaryTotal
Checked with Saudi Arabia ZATCA Tax Invoice (UBL), Saudi Arabia ZATCA Simplified Tax Invoice (UBL)