From January to october the withholding tax rate was 12%, from november it is 11%. what configuration we need to do to reflect the changes.in case we are pulling up the report,wil the changes in the tax has any affect.
there are no Standard Report that allows You to change the WT code into
the documents if the vendor master data is changed.
The only thing you can do for open items is to define a new combination
of withholding tax type and withholding tax code (now 12%) in the vendor master
data and run report RFWT0010 afterwards.
Please test it into a test System.
However, in open items, it should be possible to change the w/tax code
using transaction FB02 for invoices.
I hope this can help You.