Ashlin Designs charges sales and use tax according to Federal, State and Local government guidelines. Tax is calculated based on the shipping address and the appropriate rules for that tax jurisdiction. Note that the taxes presented at time of order submission are only an estimate, and may not take into account applicable exemptions and tax holidays. Final calculation of applicable taxes will be performed when the order ships and your credit card is charged. For Australian Customers GST tax is applicable of 10% on top of the order prior to shipping calculations.