# ibr-055

Source: https://xmlvalid.com/rules/ibr-055

> Each Preceding Invoice reference (ibg-03) MUST contain a Preceding Invoice reference (ibt-025).

- Level: error
- Rule sets: PINT Billing rules 1.1.3, PINT Billing rules (as shipped with PINT AE) 1.0.4
- Context: `cac:BillingReference`
- Test: `exists(cac:InvoiceDocumentReference/cbc:ID)`

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