# UBL-SR-48

Source: https://xmlvalid.com/rules/UBL-SR-48

> Invoice lines shall have one and only one classified tax category.

- Level: error
- Rule sets: EN 16931 rules (UBL) 1.3.17, EN 16931 rules 1.3.16 (UBL), Romanian RO e-Factura rules (UBL) 1.0.9
- Context: `cac:InvoiceLine | cac:CreditNoteLine`
- Test: `count(cac:Item/cac:ClassifiedTaxCategory) = 1`

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