Tennessee Code Title 6. Cities and Towns § 6-35-205

(b)(1) Competitive prices for all purchases and public improvements shall be obtained whenever practicable and in accordance with regulations established by ordinance, and the purchase made from or the contract awarded to the lowest responsible bidder; provided, that the city shall have the power to reject any and all bids.

(2) Formal sealed bids shall be obtained in all transactions involving the expenditure of ten thousand dollars ($10,000) or more, and the transaction shall be evidenced by written contract submitted to and approved by the council; provided, that in cases where the council indicates by formal unanimous resolution of those present at the meeting, based upon the written recommendation of the manager, that it is clearly to the advantage of the city not to contract with competitive bidding, it may authorize noncompetitive contracts.

(3) The council may also authorize the making of public improvements or the performing of any other city work by any city department or agency without competitive bidding.