Mo. Rev. Stat. § 33.202

Where a delay in submitting a fee, application, report or other form to a state agency may result in the assessment of penalties or interest by such agency, no penalty or interest may be assessed for any period during which the proper fee, or properly completed application, report or form was in the possession of the state agency in a timely manner, or for any period of delay not attributable to the reasonable and practical processing of the application, report or form by the state agency.