How do I set the sales tax so that orders are taxed at the county level?
Next to each state you want to charge sales tax at the county level, select the "T" in the drop down. This may be done in Order Management System/Settings/Sales Tax.
*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 in the Third Party Tax Database 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.