Mo. Rev. Stat. § 392.440

Any telecommunications company offering or providing the resale of either local exchange or interexchange telecommunications service must first obtain a certificate of service authority. Except as provided in section 392.450, the commission shall approve an application for a certificate for the resale of local exchange or interexchange telecommunications service upon a showing by the applicant, and a finding by the commission, after notice and hearing, that the grant of authority is in the public interest.