Mo. Rev. Stat. § 143.251: Employer's failure to withhold.

If an employer fails to deduct and withhold tax as required, and thereafter the tax against which such tax may be credited is paid, the tax so required to be deducted and withheld shall not be collected from the employer. The employer shall not be relieved thereby from liability for any penalties, interest, or additions to tax otherwise applicable in respect to such failure to deduct and withhold.