Tennessee Code Title 2. Elections § 2-2-137

(a) Notwithstanding this chapter to the contrary, a county election commission may adopt a supplemental system for maintaining registration records utilizing electronic, electromechanical or microfilm equipment. If the election commission exercises its option to scan or microfilm the original permanent record, the filmed or scanned record shall be the legal document of registration. If the election commission microfilms or scans the registration document, the original hard copy shall be retained, but may be retained at any location designated by the election commission.

(b) Beginning January 1, 2015, the coordinator of elections and the state election commission shall certify each voter registration system for purchase and use in the state. Subject to the concurrence of the state election commission, the coordinator of elections may make rules and policies as are necessary to carry out this subsection (b). In determining whether a voter registration system may be certified, the coordinator of elections and the state election commission shall consider, at a minimum, the following: