3475241 - The requirement of overwriting the withholding tax in the supplier invoice or modifying the withholding tax amount at the item level

The requirement of overwriting the withholding tax in the supplier invoice or modifying the withholding tax amount at the item level in the back-end for the supplier invoice and SAP standard field (Tax Amount) is not PSM released and not editable.

SAP Business ByDesign

1. Go to the Supplier Invoicing work center
2. Go to Invoices and Credit Memos view
3. Select the relevant Supplier Invoice
4. Select Edit & navigate to Items tab
5. Select sub tab Taxes and then Withholding Tax Details
6. Here you expect a different calculation to appear than the withholding tax rate which is derived by the system and also this SAP standard field (Tax Amount) is not PSM released and not editable.

Your requirement of overwriting the withholding tax in the supplier invoice is not supported in Business ByDesign to change/overwrite the value for Withholding tax at document item level.
it is not possible to modify the withholding tax details at the supplier invoice level. Once the withholding tax code is determined, the system will default the values for tax type, tax rate type etc. These values cannot be modified. 

This is the standard system behavior

KBA , SRD-SRM-SI , Supplier Invoicing , Problem