Goal:
Disable the set tax
Mark a tax type as non-default
Steps:
On the left-hand navigation bar, select Settings.
Under the finance section select Manage Tax Types.
Select the
button next to the current default tax.
Select Deactivate As Default.
You'll get a little confirmation message on the top right of the screen when it's successful.
Additional information:
Only users with permission to Manage Tax Types can disable the default tax.
For steps on how to mark a new tax as the default, see How to Set a Default Tax Type.