Flat Tax in Regions allows you to charge a flat tax rate for all regions you define as taxable. Only customers with a shipping address in the taxable regions will be charged tax.
To configure your cart for flat tax in tax regions, navigate to the BuyNow module and select "Setup -> Tax" from the admin menu:
The following tax setup page will be displayed:
1. Select "Flat Tax in Regions" from the radiobutton list.
2. Enter a tax rate to charge in your tax regions.
3. Click the "Tax Regions" tab and define the regions you want to charge tax in.
To learn more about managing Tax Regions, see the Tax Regions KB article.