US Sales Tax Configuration
Items that are set as taxable will calculated by the tax rate set in the Sales Tax Configuration screen. Sales tax is calculated based on the number of total taxable items in the shopping cart and the user’s registration address for downloadable items or the user’s shipping address for shippable items.
Note: Sales tax will not be applied to an order if there is not a minimum of one (1) item in the shopping cart that has been set as taxable or if the order registration address or shipping address does not match the sales tax state selected in the sales tax configuration screen.