Mo. Rev. Stat. § 148.690
Each association and credit union organized under the laws of this state and each association organized under the laws of the United States to be located in Missouri, with the date of its certificate of incorporation, or the date of the completion of the organization thereof, as the case may be, which are relevantly herein referred to as "its certificate", subsequent to May 25, 1982, shall be subject to the tax imposed by this law for the calendar year in which it receives its certificate and the first taxable year thereafter measured by its net income as defined in section 148.630, for the portion of the calendar year unelapsed on the date borne by its certificate with the rate of tax as provided in section 148.620, and with credit against said tax for all taxes and contributions for which credit is permitted by section 148.620, which taxes or contributions are paid during the portion of the calendar year unelapsed on the date of its certificate. For each other taxable year each taxpayer in this section referred to shall be subject to all the provisions of this law. Any tax imposed by this law due for the calendar year of its certificate shall be payable by each taxpayer to which this section applies to the director on or before June first of the year following the year of its certificate, and except as to this particular the provisions of sections 148.630 to 148.680 and section 148.700 shall be applicable.
§ 148.690, RSMo
Effective 5/25/1982