# ibr-001

Source: https://xmlvalid.com/rules/ibr-001

> An Invoice MUST have a Specification identifier (ibt-024).

- Level: error
- Rule sets: PINT Billing rules 1.1.3, PINT Billing rules (as shipped with PINT AE) 1.0.4
- Context: `/ubl:Invoice | /cn:CreditNote`
- Test: `normalize-space(cbc:CustomizationID) != ''`

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