How Does tax button work in my administrations page?
Tax is only applicable if the customer is in the same state as the state you enter on this configuration page. In your configuration link you must add your state letters for your shopping cart to calculate tax. Sales tax is charged if the customer is in the same state only. If you leave your state zip code empty, your shopping cart will not charge any of your clients tax. You can determine if you wish to charge tax on shipping fee or not depending on your State laws.