Tenn. Code Ann. § 67-4-1409

It is the duty of every operator liable for the collection of and payment to the municipality of any tax imposed by this part to keep and preserve for a period of three (3) years all records as may be necessary to determine the amount of such tax for which the operator may have been liable for the collection of and payment to the municipality, which records the authorized collector shall have the right to inspect at all reasonable times.