I am trying to fin out an exit or badi for Updating Tax code (MWSKZ) and Unit of Measure in transaction ME21n.
The scenario is like this...
For Purchase Orders Tax code will be defaulted from Purchasing info record or contract or parameter id for that item-vendor-plant.
If the Tax Code is not defaulted and account assignment is blank then tax code on the PO is updated according to the below mentioned table
Supplying Plant/ Receiving Plant Tax code
country 5050(NA) 20
2300 6700 E0
If the tax code on PO cannot be updated by the above table, then buyer needs to put tax code on the purchase order manually.