How do I make a buyer tax exempt?

Edited

Start by creating the tax exempt tax rate. 

On the left-hand menu, go to "Tax Rates" under "Invoicing and Payments."

Click "Create" to create a new tax rate.

Click "save." 

Now, to apply it to a user, navigate to your "User" menu on the left-hand side. 

Click the orange pencil beside their name to edit their account. 

Scroll to the bottom and find the "invoicing" dropdown.

Under "tax rate" choose "tax exempt."