3548350 - Condition type &1 is already assigned to another withholding tax type.

Error Condition type &1 is already assigned to another withholding tax type is raised in configuration activity Assign Condition Type to Withholding Tax Type (Configuration Activity ID 104402)

SAP S/4HANA Public Cloud Edition 

In configuration activity Assign Condition Type to Withholding Tax Type the same condition type is assigned to more than one WTax Type 

You can’t assign this condition type to multiple tax type. You need a different condition type for each withholding tax type. Use the Assign Condition Type to Withholding Tax Type configuration activity to check your condition type assignments and adjust as necessary.

By default error Condition type &1 is already assigned to another withholding tax type is an Information message. You can set it as a Warning or an Error. The latter blocks further actions. To do this, use configuration activity Change Message Control for Withholding Tax (Configuration Activity ID 104402). 

Setting Up Withholding Tax in the Sales Process

7Q459 , KBA , FI-AP-AP-Q-2CL , Withholding Tax (Calculation) (Public Cloud) , How To