Tax regions allow you to define taxable regions in your store.
To define tax regions, navigate to the BuyNow module and select "Setup -> Tax" from the admin menu:
Next, click the “Tax Regions” tab:
To add a new Tax Region, click the “Add Tax Region” button:
After clicking the “Add Tax Region” button the following screen will be displayed:
Enter the country, region and/or postal code for your tax region.
Select the tax exempt option. Select "Never Tax Exempt" to make a region taxable.
Click the save button to save your tax region