Mo. Rev. Stat. § 379.300: Failure to make return — director to proceed.

If any company or association shall fail or refuse to make the return required by sections 379.205 to 379.310*, the said director shall assess the tax against said company or association at the rate herein provided for on such amount of premiums as he shall deem just and the proceedings thereon shall be the same as if the return had been made.