Mo. Rev. Stat. § 313.826: Tax withholdings, electronic gaming device jackpots and table game jackpots in excess of certain amount, percentage.

Each excursion gambling boat licensed by the commission shall withhold for state income tax purposes from electronic gaming device jackpots or table game jackpots of twelve hundred dollars or more an amount equal to four percent of the prize. Withholdings made pursuant to this section shall be subject to the withholding tax provisions pursuant to sections 143.191 to 143.261, including section 143.261.