Use the online voter registration form at https://sos.tn.gov/products/elections/how-do-i-register-vote or download a Tennessee voter registration application and submit the application to your local county election commission. In order to participate in an election, a qualified voter must be properly registered no later than thirty (30) days before the election. The election commission office will process any voter registration form that has been postmarked at least thirty (30) days before the election.