# ibr-028

Source: https://xmlvalid.com/rules/ibr-028

> The Item gross price (ibt-148) MUST NOT be negative.

- 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:CreditNoteLine`
- Test: `(cac:Price/cac:AllowanceCharge/cbc:BaseAmount) >= 0 or not(exists(cac:Price/cac:AllowanceCharge/cbc:BaseAmount))`

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