Tenn. Code § 9-21-801
The governing body of a local government may issue interest-bearing tax anticipation notes for the purpose of meeting appropriations made for the current fiscal year in anticipation of the collection of taxes and revenues of that fiscal year in amounts not exceeding sixty percent (60%) of such appropriation; provided, that the sale of the notes shall first be approved by the comptroller of the treasury or the comptroller's designee. The notes may be renewed from time to time and money may be borrowed from time to time for the payment of any indebtedness evidenced thereby, but all such notes shall mature not later than the close of the current fiscal year. If taxes and revenues are found to be overestimated and it becomes impossible to pay the notes prior to the close of the current fiscal year, application shall be made to the comptroller of the treasury or the comptroller's designee within ten (10) days prior to the close of the current fiscal year for permission to issue funding bonds to cover the unpaid note balances in the manner provided by chapter 11 of this title, or as otherwise provided for in a manner approved by the comptroller of the treasury or the comptroller's designee.
T.C.A. § 9-21-801