For 2026, the sales tax rate in Cook County, Illinois stands at 10.25% — a combination of the 6.25% state rate and 4% local levy. The county's 5,150,000 residents make it an important market in the region.
For a $500 purchase in Cook County, the sales tax would be $51.25, bringing the total to $551.25.
Business Compliance in Cook 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 5,150,000, Cook County offers significant market potential for businesses of all sizes.