# BR-CIUS-PT-34

Source: https://xmlvalid.com/rules/BR-CIUS-PT-34

> The Seller identifier (BT-29) or the Bank assigned creditor identifier (BT-90) shall be filled.

- Level: error
- Rule sets: CIUS-PT rules (Portugal, UBL) 2.1.1
- Context: `cac:AccountingSupplierParty`
- Test: `exists(cac:Party/cac:PartyIdentification) and not(cac:Party/cac:PartyIdentification/cbc:ID)`

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