Businesses operating in St. Louis County, Missouri face a combined sales tax rate of 9.113% in 2026. The 4.888% local rate is added to the 4.225% state base. Home to 1,004,125 residents, the county offers substantial commercial opportunities.
For a $500 purchase in St. Louis County, the sales tax would be $45.56, bringing the total to $545.57.
Business Compliance in St. Louis County
Businesses must register with the Missouri Department of Revenue to collect and remit sales tax. Filing frequency depends on sales volume. With a population of 1,004,125, St. Louis County offers significant market potential for businesses of all sizes.