From the help menu:
To deactivate a tax rate:
Important! You will NOT be able to reactivate a tax rate. If you need it for future use, you’ll have to create a new one.
- Select Taxes from the left menu.
- In the Sales Tax Center, go to the Related Tasks section and select Add/edit tax rates and agencies.
- Select a tax rate name then select Deactivate.
- Select Continue on the dialog box.
there is no way to reactivate a sales tax rate.
