Mo. Rev. Stat. § 105.545

Every person required to file any report under the provisions of sections 105.533 to 105.555 shall maintain records on the matters required to be reported that will provide in sufficient detail the necessary basic information and data from which the documents filed with the department may be verified, explained or clarified, and checked for accuracy and completeness, and shall include vouchers, worksheets, receipts, and applicable resolutions. Such records shall be kept available for examination for a period of not less than five years after the filing of the documents based on the information that they contain.