Tenn. Code Ann. § 56-4-105: Refund of erroneously paid amounts

(a) With respect to any revenues or receipts collected by the department, any other law to the contrary notwithstanding, the amounts determined to have been erroneously paid may be refunded by the procedure developed by the commissioner of finance and administration and approved by the comptroller of the treasury.

(b) The procedure shall provide that no refund shall be made unless within three (3) years from December 31 of the year in which the erroneous payment was made, the refund is either requested by the claimant or made by the state on its own motion.