Tenn. Code Ann. § 41-4-127

The county legislative bodies of counties that have no jail may appropriate a contingent fund in an amount sufficient to pay all contingent expenses in transporting prisoners to and from jail, the appropriation to be made from time to time, so that the sheriff may be able, at any time, upon application to the county trustee, to procure the money necessary, for which the sheriff shall execute a receipt, showing the amount received, which receipt shall clearly set forth for which prisoner the money is expended.