# ibr-063

Source: https://xmlvalid.com/rules/ibr-063

> The Buyer electronic address (ibt-049) MUST have a Scheme identifier.   

- Level: error
- Rule sets: PINT Billing rules 1.1.3, PINT Billing rules (as shipped with PINT AE) 1.0.4
- Context: `cac:AccountingCustomerParty/cac:Party/cbc:EndpointID`
- Test: `exists(@schemeID)`

Validate a document against these rules: https://xmlvalid.com/validate