Mo. Rev. Stat. § 301.160

Upon approval of the application for registration of a motor vehicle or trailer and when the required fee has been paid to the department of revenue, the department shall forward or deliver to the applicant the registration receipt and the number of license plates prescribed for the vehicle or trailer by section 301.130, or renewal tabs if appropriate. The attachment to the motor vehicle or trailer specified in the application of current license plates shall be prima facie evidence that the fees have been paid for such license.