Is it possible to change the "Tax Calculation Method Based On" for different Customer Groups?
For Example, General should be Unit Price, and Retailer should be Total.
I know, its possible with different Websites, but i want it inside my current one.
Sales > Tax > Customer Tax Classes - Add a new Customer Tax Class for these customers.
Sales > Tax > Product Tax Classes - Add a new Product Tax Class for the selected products.
Sales > Tax > Manage Tax Zones and Rates - Add a new Tax Rate, applying it the the United Kingdom and a Rate Percent of "0."
Sales > Tax > Manage Tax Rules - Add a new tax rule, applying it to the Customer Tax Class, Product Tax Class and Tax Rate you just created in Steps 1, 2 and 3. This tax rule is what ties together the eligible customers and eligible products and applies the tax rate of "0" to those products.
Sales > Tax > Manage Tax Rules - Make sure your existing rules apply the proper Tax Rates for other Customer Tax Classes to the new Product Tax Class you created in Step 2. You want to ensure your non-eligible customers still have the proper tax applied.
Customers > Customer Groups - Add a new Customer Group for the eligible customers and assign it the Customer Tax Class that you created in Step 1.
Catalog > Manager Products - Bulk edit the products that should be tax exempt for eligible customers and update their Tax Class to the new Product Tax Class you just created in Step 2</div>