Mo. Rev. Stat. § 94.870
In addition to all other taxes prescribed by law, the governing body of any municipality of the third classification with a population of at least fifteen thousand but not more than eighteen thousand inhabitants located within a county with a population of at least thirty-five thousand but not more than forty-five thousand inhabitants which has a total assessed valuation of at least two hundred seventy-five million dollars but not more than three hundred twenty-five million dollars, the governing body of any county with a population of at least twenty thousand but not more than twenty-five thousand which has a total assessed valuation of at least one hundred twenty million dollars but not more than one hundred forty million dollars or any municipality located in such county and the governing body of any county with a population of at least twenty-eight thousand but not more than thirty-one thousand which has a total assessed valuation of at least two hundred fifty-five million dollars or any municipality located in such county and the governing body of any county with a population of at least twenty-five thousand but not more than thirty thousand which has a total assessed valuation of at least two hundred million dollars but not more than two hundred five million dollars or any municipality located in such county, or any city located partially but not wholly within a county of the third classification with a population of at least thirty-nine thousand inhabitants may impose, by ordinance or order, a tax on the price paid or charged to any person for rooms or accommodations paid by transient guests of hotels, motels, condominium units, campgrounds, and tourist courts situated within the political subdivision, at a rate not to exceed four percent of such price paid or charged. As used in this section, the term "hotel", "motel", or "tourist court" means any structure or building, under one management, which contains rooms furnished for the accommodation or lodging of guests, with or without meals being provided, including bed and breakfast facilities, and kept, used, maintained, advertised, or held out to the public as a place where sleeping accommodations are sought for pay or compensation to transient guests, and the term "campground" means real property, other than state-owned property, which contains parcels for rent to transient guests for pay or compensation, which may include temporary utility hook-ups for use by the transient guests, and where such transient guests generally use tents, recreational vehicles or some other form of temporary shelter while on the rented premises. Shelters for the homeless operated by not-for-profit organizations are not a hotel, motel, or tourist court for the purposes of this section. As used in this section, the term "transient guest" means a person who occupies a room or rooms in a hotel, motel, campground, or tourist court for thirty consecutive days or less.
§ 94.870, RSMo