Mo. Rev. Stat. § 301.344: Municipality not to require permits of certain wreckers, exceptions when — county permits, when.

No town, city, village or municipality shall require a fee, permit or license for any reason from any wrecker or tow service business registered with the United States Department of Transportation, however, any county or a city not within a county of this state shall require such a fee, permit or license of any such business physically located in such county or city not within a county or of any such business which conducts more than fifty percent of its wrecker or tow service business activities in such county or city not within a county.