Tennessee Code Title 5. Counties § 5-8-207

(a)(1) Every county official handling public funds shall be required to maintain an official bank account in a bank or banks within this state, and shall, within three (3) days after the receipt by such county official of any public funds, deposit the funds to the credit of such county official's official bank account, or bank accounts. Each county official maintaining an official bank account is authorized to enter into such agreements with banks and other financial institutions as necessary for the maintenance of collateral to secure the funds on deposit; provided, that the deposit of county funds in banks or financial institutions by a county trustee shall be done in accordance with § 5-8-201.

(2) All funds deposited with a bank or other financial institution shall be secured by collateral in the same manner and under the same conditions as state deposits under title 9, chapter 4, parts 1 and 4, or as provided in a collateral pool created under title 9, chapter 4, part 5.

(3) This requirement shall not prohibit a county official handling public funds from maintaining a petty cash fund in an account sufficient for the transaction of the official business of such county official's office.