# F-INV046

Source: https://xmlvalid.com/rules/F-INV046

> One Contact class must be present

- Level: error
- Rule sets: OIOUBL 2.1 Invoice rules (Denmark) 1.17.2
- Context: `doc:Invoice/cac:AccountingCustomerParty/cac:Party`
- Test: `count(cac:Contact) = 1`

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