Tenn. Code Ann. § 8-4-108

(1) The comptroller of the treasury shall perform all such services as may be required of the comptroller of the treasury by law or by resolution of the general assembly. The comptroller is authorized to provide such services to a county or other local government as may be requested by that entity and determined by the comptroller to be appropriate, and to charge that entity an administrative fee with respect thereto.(b) This section shall not be construed either to extend or limit the authority of the division of property assessments with respect to taxpayer audits and reviews to the extent such authority exists under present law.