BR-KSA-42
The buyer name (BT-44) must be present in the tax invoice and associated credit notes and debit notes (KSA-2, position 1 and 2 = 01).
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.
cac:AccountingCustomerParty/cac:Party
(cac:PartyLegalEntity/cbc:RegistrationName) != ''
Checked with Saudi Arabia ZATCA Tax Invoice (UBL), Saudi Arabia ZATCA Simplified Tax Invoice (UBL)