All Sales Tax is managed at Settings/Sales Tax in the Order Management System. For each state/province for which you wish to charge sales tax, use the select box to the right of the state/province abbreviation to select the Rate Source. The Rate Source options are:
T (Third Party Tax Data): Use the sales tax rate data provided to Nexternal by a Third Party. The data includes over 40,000 sales tax records at the state, county, and city level and is updated monthly. When an order is placed, the sales tax rate is looked up based on the Ship To State and Zip Code; if no match is found, the State Average is used. This option is not available for the Canadian Provinces.
A (State Average): Use Nexternal's average state sales tax rate table. When you select this option, the State Average rate appears in the Tax Rate textbox, but may not be edited.
O (Own Rate): Define your own sales tax rate for the state/province via the Tax Rate textbox.
U (Undisclosed): Sales tax is listed as "TBD" to customers in the Online Store when an order is placed. You may then manually enter the sales tax rate in the Order Management System before shipping the order.