SAP Message 7Q631 - ... CoCde &, W/holding tax type &: No numbering class assigned

Diagnosis
A numbering class has not been assigned to the combination of companycode and withholding tax type.
Withholding tax types exist that are relevant to numbering. The systemcannot determine a certificate number because the Customizing settingsare incomplete.

System Response
Payment cannot be made.

Procedure
Assign a numbering class to the combination of company code andwithholding tax type.