Mo. Rev. Stat. § 130.047
Any person who is not a defined committee who makes an expenditure or expenditures aggregating five hundred dollars or more in support of, or opposition to, one or more candidates or in support of, or in opposition to, the qualification or passage of one or more ballot measures, other than a contribution made directly to a candidate or committee, shall file a report signed by the person making the expenditures, or that person's authorized agent. The report shall include the name and address of the person making the expenditure, the date and amount of the expenditure or expenditures, the name and address of the payee, and a description of the nature and purpose of each expenditure. Such report shall be filed with the appropriate officer having jurisdiction over the election of the candidate or ballot measure in question as set forth in section 130.026 no later than fourteen days after the date of making an expenditure which by itself or when added to all other such expenditures during the same campaign equals five hundred dollars or more. If, after filing such report, additional expenditures are made, a further report shall be filed no later than fourteen days after the date of making the additional expenditures; except that, if any such expenditure is made within fourteen days prior to an election, the report shall be filed no later than forty-eight hours after the date of such expenditure. The provisions of this subsection shall not apply to a person who uses only the person's funds or resources to make an expenditure or expenditures in support of or in coordination or consultation with a candidate or committee; provided that, any such expenditure is recorded as a contribution to such candidate or committee and so reported by the candidate or committee being supported by the expenditure or expenditures.
§ 130.047, RSMo