Add Postal Code: Click to add a new postal code tax rate to your postal code tax table. Once added, specify the postal code and the tax rate percentage for that postal code above.
Note: It is usually a good idea to import/export your tax postal code table since it is typical to have a very large amount of postal codes.

Also check shipping postal code to include tax: By default, only the customer's billing information is checked to determine whether to charge tax. Enable this option to also check the customer's shipping information to include tax.

Enable sales tax on shipping charges: Enable this option to include sales tax for the order's shipping charges. This option will only apply to orders who qualify for sales tax.