I'm trying to use Sage 50 to make customer exempt with Avatax.
In Sage 50 go to the Avatax Configuration and click the Entity use Codes tab.
Click Synchronize with PeachTree to pick up new customers.
Find the customer and double click them.
Select the entity use code you would like to apply.
Your customer will now be associated with the entity use code you have selected.
If this is a custom code you will need to make a tax rule in the admin console that tells the system to charge a specific rate for that Entity use code.