Mo. Rev. Stat. § 137.392: Clerk to deliver tax books to collector, when — extension of time.

On or before October thirty-first of each year, the county clerk shall deliver the real estate and personal property tax books, with the taxes correctly extended thereon, to the county collector, except that in counties in which the county clerk does not prepare the real estate and tangible personal property tax bills, the books shall be returned to the county collector on or before September fifteenth of each year. The time may, for good cause shown, be extended by the county commission for a period not to exceed ten days after September fifteenth.