# CF409

Source: https://xmlvalid.com/rules/CF409

> Phone Number Maximum length is 20 characters - ….

- Level: error
- Rule sets: MyInvois validations of LHDN (Malaysia) MyInvois SDK of 25 September 2026
- Context: `/*/cac:AccountingSupplierParty/cac:Party | /*/cac:AccountingCustomerParty/cac:Party`
- Test: `string-length($phone) le 20`

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