St. Clair County, IL Car Tax & Registration (2026)
In St. Clair County, a dealer car purchase is taxed at about 7.35% (the countywide base — cities can be higher), on top of the statewide $165 title and $151 registration fees. For a private-party purchase, St. Clair County uses Illinois's flat statewide tax table (RUT-50) — no extra county tax. St. Clair County requires emissions testing in certain ZIP codes.
Verified July 2026 from official sources. How we verify fees.
What you'll pay in St. Clair County
- Dealer sales tax: ~7.35% base (varies by city/ZIP)
- Private-party tax: flat RUT-50 table (statewide)
- Title: $165 · Registration: $151 (statewide)
- Emissions: required in some ZIPs
How the tax works
Dealer purchases are taxed at your registration-address rate, which varies within St. Clair County by city — resolve your exact rate on the Illinois DOR Tax Rate Finder. Private-party sales use the state RUT-50 flat table (based on the vehicle's price and age), shown on our Illinois title & tax page.
Frequently asked questions
What is the car sales tax in St. Clair County, IL?
Dealer purchases are taxed at about 7.35% (countywide base; cities can be higher). Private-party sales use Illinois's flat statewide RUT-50 table.
Does St. Clair County require emissions testing?
St. Clair County requires emissions testing in certain ZIP codes.
How much is car registration in St. Clair County?
Title is $165 and registration is $151 statewide. The county-specific part is the dealer sales-tax rate (~7.35%) on a purchase.