AP Tax code issue

[Triveni]

Hi All ,

There is an issue with Tax code in 11i (11.5.10.2 V)

Scenario:
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user is using the Payables Bizz support responsibility,

As the taxcode enddated we could n't able to see the taxcode in the Invoice workbench.

The taxcode is enddated at withholding tax against a taxcode ex: WER N SER ( setup/tax/code at bottom end click on withholding tax which will opens a form , on that the taxcode was enddated)

Now user would like to disable the Taxcode in frontend by disabling the checkbox (Setup/tax/code - putting cursor agaist taxcode ex: WER N SER ) its throwing an error "FRM:Field is protected against update" , due to this its appearing in the Tax Listing Report as enabled.

please let me know the possibilities of Disabling that taxcode.

please find the following My assumptions for possibilities ?

1)was there is any concurrent program which will update the taxcode enable/disable ?

2) we need to update the change threw back end , if so please let me know that back end update query ?

Please let me know the solution for the issue as soon as possible.

Thanks
Triveni