Mo. Rev. Stat. § 105.375: Officer compensated solely by fees to reimburse county for contributions.

Any county officer who is compensated wholly by fees derived from sources other than county or state moneys shall pay into the county treasury out of fees received by him amounts equal to the contributions required to be paid by the county under section 105.370 and shall collect from all deputies, assistants and employees in his office and turn over to the officer or agent of the county charged with the payment thereof to the Internal Revenue Service the amounts required to be collected and paid under section 105.370.