Mo. Rev. Stat. § 488.5030

To collect on past-due court-ordered penalties, fines, restitution, sanctions, court costs, including restitution and juvenile monetary assessments, or judgments to the state of Missouri or one of its political subdivisions, any division of the circuit court may contract with public agencies or with private entities operating under a contract with a state agency or the office of state courts administrator. Any fees or costs associated with such collection efforts shall be added to the amount due, but such fees and costs shall not exceed twenty percent of the amount collected.