Service or maintenance contracts on equipment or machinery entered into at the time of purchase do not require bidding, regardless of cost. Renewal of these contracts does not require bidding, provided the contract contains a renewal clause.
19 O.S. § 1501(A)(3)(d)

Other service or maintenance contracts must be bid on if the costs exceed Twenty-Five Thousand Dollars ($25,000.00) and are acquired AFTER the purchase. Follow normal bidding procedures as outlined in Chapter Five, “Public Competitive Bidding Act.”

All contracts (and renewals) must be approved by the board of county commissioners.