St Charles County Registrar
  The St. Charles County Registrar is responsible for keeping track of tax rates levied by all of the county‚Äôs political subdivisions.
   
  Missouri Department of Revenue
  The Missouri Department of Revenue administers Missouri's business tax laws, and collects sales and use tax, employer withholding, motor fuel tax, cigarette tax, financial institutions tax, corporation income tax, and corporation franchise tax. Different types of businesses must register for different types of taxes.
   
  Business and Aircraft Personal Property Assessment Form 
   
  Tax Exempt Application