Mo. Rev. Stat. § 327.281: Unauthorized practice prohibited.

No person, including any duly elected county surveyor, shall practice as a professional land surveyor in Missouri as defined in section 327.272 unless and until there is issued to such person a license or a certificate of authority certifying that such person has been duly licensed as a professional land surveyor in Missouri, and unless such license or certificate has been renewed as provided in section 327.351.