Tennessee Code Title 65. Public Utilities and Carriers § 65-4-111

(a) The commission has the power, after hearing, upon notice, by order in writing, to require every public utility as defined in § 65-4-101 to keep its books, records, and accounts so as to afford an intelligent understanding of the conduct of its business, and to that end to require every such public utility of the same class to adopt a uniform system of accounting. The accounting system shall conform, where applicable, to any system adopted or approved by the interstate commerce commission.

(b) The commission also has the power to require each such utility to furnish annually, or at such other times as the commission may require, a detailed report of finances and operations as shown by such system of accounts.