Tenn. Code § 9-21-505
The sale of bond anticipation notes shall first be approved by the comptroller of the treasury or the comptroller's designee, and the notes shall be issued for the express purpose of providing funds in anticipation of the sale of bonds. All such notes shall be issued for a period not to exceed two (2) years from the date of issue; provided, that with the approval of the comptroller of the treasury or the comptroller's designee the notes may be extended or renewed for not more than two (2) additional periods not exceeding two (2) years each. Each year that extension or renewal notes are outstanding, the local government shall retire a portion thereof equal to not less than one-twentieth (1/20) of the original principal amount of the notes, and to that end, the resolution authorizing any such issue of extension or renewal notes shall provide for the notes to mature serially, and may provide that the notes shall be subject to redemption prior to maturity at the option of the local government. In approving any issue of extension or renewal notes, the comptroller of the treasury or the comptroller's designee may waive the requirement of periodic retirement. Application to the comptroller of the treasury or the comptroller's designee for the extension or renewal of any such notes shall be by resolution of the governing body. Notwithstanding this section, the comptroller of the treasury or the comptroller's designee shall not be required to approve the issuance or extension of any bond anticipation note issued in anticipation of the issuance of a bond or other debt obligation to a state or federal agency.
T.C.A. § 9-21-505