# ibr-085

Source: https://xmlvalid.com/rules/ibr-085

> Start date of line period (ibt-134) MUST be within invoice period (ibg-14).

- Level: error
- Rule sets: PINT Billing rules 1.1.3, PINT Billing rules (as shipped with PINT AE) 1.0.4
- Context: `cac:InvoiceLine/cac:InvoicePeriod | cac:CreditNoteLine/cac:InvoicePeriod`
- Test: `(cbc:StartDate >= xs:date(../../cac:InvoicePeriod/cbc:StartDate)) or not(cbc:StartDate) or not(../../cac:InvoicePeriod/cbc:StartDate)`

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