Tenn. Code Ann. § 54-12-309: Deposit of bidders required

(a) Each person bidding for the work shall deposit with the treasurer of the board of directors in cash or certified check a sum equal to ten percent (10%) of the amount of the bid, not in any event, however, to exceed ten thousand dollars ($10,000).

(b) The deposit shall be returned to the bidder if the bid is not successful, or, if successful, to be retained as a guarantee only of the bidder's good faith in entering into the contract.