Mo. Rev. Stat. § 138.434
Any first class charter county or a city not within a county may require by ordinance or charter the reimbursement to a taxpayer for the amount of just and reasonable appraisal costs, attorney fees and court costs resulting from an evidentiary hearing before the state tax commission or a court of competent jurisdiction if such appeal results in a final decision reducing the appraised value of residential property by at least fifteen percent or the appraised value of utility, industrial railroad and other subclass three property by at least twenty-five percent from the appraised value determined by the board of equalization for that tax year. The commission or court awarding such fees and costs shall consider the reasonableness of the fees and costs within the context of the particular case. Such fees and costs shall not exceed one thousand dollars for a residential property appeal. Such fees and costs for utility, industrial railroad or other subclass three property appeals shall not exceed the lesser of four thousand dollars or twenty-five percent of the tax savings resulting from the appeal. The provisions of this section shall only apply to the first contested year when cases are tried on a consolidated basis.
§ 138.434, RSMo