Mo. Rev. Stat. § 316.045: Penalty for delinquent payment of license tax.

The county commissions of all counties of class one, in addition to other penalties imposed, are empowered in addition to the license tax imposed by section 316.040, to levy a penalty of one percent per month upon any person, firm or corporation who fails to pay the license tax imposed by section 316.040 by the first day of February of each year.