Mo. Const. art. X, § 11(b)
Mo. Const. art. X, § 11(b). Limitations on local tax rates
Any tax imposed upon such property by municipalities, counties or school districts, for their respective purposes, shall not exceed the following annual rates: For municipalities—one dollar on the hundred dollars assessed valuation; For counties—thirty-five cents on the hundred dollars assessed valuation in counties having three hundred million dollars, or more, assessed valuation and having by operation of law attained the classification of a county of the first class; and fifty cents on the hundred dollars assessed valuation in all other counties; For school districts formed of cities and towns, including the school district of the city of St. Louis—two dollars and seventy-five cents on the hundred dollars assessed valuation; For all other school districts—sixty-five cents on the hundred dollars assessed valuation. [Effective - 03 Dec 1998 , see footnote]