Missouri Revised Statutes Title X. Taxation and Revenue § 144.230. Assessed penalty and tax due, when

Any amount assessed or any additional amount assessed by the director of revenue under the provisions of sections 144.010 to 144.525, together with the penalty, if any there be, shall be due and payable from the person to the director of revenue sixty days after the service upon or mailing to the person of notice of such assessment or such additional assessment, except only for such amounts as to which the person has filed a petition for review with the administrative hearing commission.