Mo. Rev. Stat. § 136.365: Appeal, taxpayer's right to, notice to be given, when.

Subject to chapter 143 and chapter 144, the director shall inform all taxpayers against whom an assessment of additional tax, interest or penalty has been issued of the taxpayer's right to appeal. Such written notification shall accompany each notice of assessment and shall set forth the time period within which the taxpayer must file an appeal, and how to proceed with the appeal should he desire.