The Vinoshipper Create an Order API will automatically calculate the appropriate taxes and state fees, but if you want to display an estimate of tax and shipping costs to your customer prior to submitting the order, you can use the Estimate Taxes and Estimate Shipping APIs. The Estimate Shipping API will return a list of available shipping rates, and the Estimate Taxes API will accept an optional shipping rate as in some cases shipping is taxable. Only the postal code is required to return an estimate, but rates will be more accurate with a fully complete address.