St. Louis County, MO Car Tax & Registration (2026)
In St. Louis County (around Clayton), a car purchase is taxed at roughly 9.24% combined — Missouri's 4.225% state tax plus local tax set by your home address (special districts can push it higher). St. Louis County is in the St. Louis-area Gateway program, so an emissions test is required before you renew. A safety inspection is required statewide, but cars under 10 years old and 150,000 miles are exempt.
Verified July 2026 from official sources. How we verify fees.
What you'll pay in St. Louis County
- Combined sales tax: ~9.24% (state 4.225% + local, by address)
- Emissions test: required (St. Louis area)
- Safety inspection: statewide (exempt if under 10 yrs & 150k mi)
- Title: $8.50 · Registration: by horsepower (statewide)
How the tax works
Missouri collects sales tax at titling based on your home address, not the dealer's — so two buyers of the same car pay different rates. The ~9.24% shown is typical around Clayton; special taxing districts can add more at a specific address. Missouri also assesses an annual county personal property tax on vehicles. Estimate the purchase cost on our Missouri title & tax page.
Frequently asked questions
What is the car sales tax in St. Louis County, MO?
About 9.24% combined around Clayton — Missouri's 4.225% plus local tax. Missouri charges it by your home address, so special districts can make your exact rate higher.
Does St. Louis County require an emissions test?
St. Louis County is in the St. Louis-area Gateway program, so an emissions test is required before you renew. Only St. Louis City, St. Louis County, St. Charles, and Jefferson County require emissions in Missouri.
Do I need a safety inspection in St. Louis County?
Missouri requires a safety inspection statewide, but vehicles under 10 model years old and under 150,000 miles are exempt — so most newer cars skip it.