BR-DE-6

The rule requires that the seller contact ('Seller contact telephone number', BT-42) includes a telephone number. In UBL, the element cbc:Telephone inside the seller contact must be present and contain a non-empty value after ignoring surrounding whitespace. In CII, ram:TelephoneUniversalCommunication/ram:CompleteNumber must be present and non-empty. A document fails when that element is missing or contains only whitespace.

Add a non-empty telephone number to the seller contact. In UBL, ensure /ubl:Invoice/cac:AccountingSupplierParty/cac:Party/cac:Contact (or the CreditNote equivalent) contains cbc:Telephone with a value. In CII, ensure ram:DefinedTradeContact contains ram:TelephoneUniversalCommunication/ram:CompleteNumber with a value. The rule does not check a specific format, only that the value is not empty.