Businesses operating in St. Clair County, Illinois face a combined sales tax rate of 8.1% in 2026. The 1.85% local rate is added to the 6.25% state base. Home to 260,000 residents, the county offers substantial commercial opportunities.
For a $500 purchase in St. Clair County, the sales tax would be $40.50, bringing the total to $540.50.
Business Compliance in St. Clair County
Businesses must register with the Illinois Department of Revenue to collect and remit sales tax. Filing frequency depends on sales volume. With a population of 260,000, St. Clair County offers significant market potential for businesses of all sizes.