Election Authority Services Board of Equalization FAQs Contact Employment	County Clerk's Services: Missouri Sales / Use Tax Exemption Contact the County Clerk's Office for an application that must be filled out and sent to the Department of Revenue or you can go to their Web site at www.dor.state.mo.us for a copy of the form. (You will have to go to their menu under "Taxes" then "Forms" then "Sales Tax"). Copyright © 1999-2000 Jefferson County, Missouri All rights reserved.