Property tax in St. Clair County, Illinois
In St. Clair County, the property tax bill comes from the St. Clair County Treasurer (County Collector). Every due date for the 2025 Real Estate Tax bill has passed, and the county had not posted the next cycle's dates when we checked. You can look up and pay the bill on the county's own payment page. Taken from St. Clair County's own pages, checked September 23, 2026.
The median property tax bill in St. Clair County, Illinois is $3,665 a year, which is about 2.03% of the county's median home value of $180,300. That effective rate is higher than the typical Illinois county (1.81%) and higher than the national median (0.81%). These are American Community Survey 5-year estimates (2024); your own bill depends on your home's assessed value and any exemptions.
Who sends the property tax bill in St. Clair County, and how do you pay it?
The bill comes from the St. Clair County Treasurer (County Collector). The value it is based on is set by a separate office, the St. Clair County Assessor's Office (Supervisor of Assessments), which is who to ask if the value looks wrong. For how to look up and pay the bill, go to the county's own payment information.
Illinois bills a year behind: the 2025 taxes were billed in late May 2026 and are paid during 2026. The county bill carries the taxes of every local district, including cities and schools, and the Treasurer passes them on. Property is reassessed on a four-year cycle that rotates among the county's 22 townships, assessment changes are published township by township each year, and the appeal window runs from each township's publication date. Online payments run through the county's payment portal, operated by MuniPay; cards cost 2.5% (at least $2) and electronic checks a small flat fee. The Treasurer also offers an optional monthly payment plan through EquaPay for the next year's bill, which does not change the due dates.
When are property taxes due in St. Clair County?
Every due date for the 2025 Real Estate Tax (payable in 2026) bill has passed, and St. Clair County had not posted the next cycle's dates when we checked on September 23, 2026. If that bill is still unpaid, the late-payment rules below apply to it. Counties usually repeat the schedule, but confirm the new dates on your next bill. For the 2025 Real Estate Tax (payable in 2026) bill, St. Clair County splits the bill into 2 payments, the first due July 1, 2026 and the last September 1, 2026. An installment not paid by its due date is delinquent the next day and carries interest of 1.5% a month or part of a month under state law. Unpaid 2025 taxes must be paid by 4:30 p.m. Friday, September 18, 2026 to stay off the delinquent list published in the newspaper, and by 4:30 p.m. Friday, October 30, 2026 to avoid the tax sale on Monday, November 2, 2026. On those two days online payments stop at 3 p.m. and postmarks are not accepted. The county marks all of these dates as tentative.
| Payment | Due | Note |
|---|---|---|
| First installment | July 1, 2026 (passed) | Already past for this cycle. July 1, 2026 was a Wednesday. Under state law a mailed payment postmarked on or before the due date is on time. |
| Second installment | September 1, 2026 (passed) | Already past for this cycle. September 1, 2026 was a Tuesday. Local banks accept payments only through this date; after it, pay the Treasurer directly or online. |
From St. Clair County's published schedule, checked September 23, 2026. If a date falls on a weekend or holiday, the county's own rules on the next business day apply.
Estimate the property tax on a home in St. Clair County
Enter a home's market value for a ballpark at St. Clair County's average effective rate of 2.03% (Census). The real bill depends on the home's assessed value, the millage where it sits and any exemptions.
Estimated property tax: $3,660 / year
Property tax in St. Clair County at a glance
| Measure | Value |
|---|---|
| Median annual property tax | $3,665 |
| Median home value | $180,300 |
| Effective tax rate | 2.03% |
| Typical Illinois county rate | 1.81% |
| National median county rate | 0.81% |
Effective rate = median real estate taxes paid divided by median home value. Source: U.S. Census Bureau, American Community Survey 5-year estimates.
How does St. Clair County compare in Illinois?
Among Illinois's 102 counties, St. Clair County has the 27th highest effective property-tax rate: 26 rank higher and 75 rank lower. That is on the higher side for Illinois. Nationally, it ranks 75th of 3135 US counties by effective rate. See every Illinois county ranked.
How much do homeowners in St. Clair County actually pay?
The median is only the middle bill. Across St. Clair County's 69,023 owner-occupied homes, 54.5% pay $3,000 or more a year in property tax, 68.6% pay at least $2,000, and 7.5% pay under $800. Another 8.4% report paying no property tax at all, which usually means an exemption covers the whole bill.
| Annual bill | Homes | Share |
|---|---|---|
| Under $800 | 5,191 | 7.5% |
| $800 to $1,499 | 6,017 | 8.7% |
| $1,500 to $1,999 | 4,580 | 6.6% |
| $2,000 to $2,999 | 9,756 | 14.1% |
| $3,000 or more | 37,652 | 54.5% |
| No property tax paid | 5,827 | 8.4% |
Owners with a mortgage pay a median of $4,189 and owners without one pay $2,871. Owners who have paid off a home have usually held it longer, and in states that cap how fast an existing owner's assessment can rise, long-held homes carry lower assessed values. Census table B25103.
How does the St. Clair County property tax bill compare with local incomes?
The median property tax bill of $3,665 is about 4% of the median income of St. Clair County homeowner households, $90,696 a year. That compares two middles, so a retiree in a long-held home can pay a far larger share. 68.4% of St. Clair County's occupied homes are lived in by their owners; renters pay property tax too, just folded into rent.
Have property taxes gone up in St. Clair County?
Yes. The median bill went from $2,868 in 2015-2019 to $3,665 in 2020-2024, a 27.8% rise. Over the same span the median home value moved 40.9%, from $128,000 to $180,300. Bills rose more slowly than values, which is what assessment caps and falling millage rates do: the county is taxing a smaller share of each home's worth.
Two Census ACS 5-year periods with no survey years in common, in each period's own dollars. A change counts only if it exceeds the combined 90% margin of error.
Property tax in counties next to St. Clair County
St. Clair County borders 7 counties, 2 of them across the state line.
| County | Effective rate | Median bill | Median home value |
|---|---|---|---|
| St. Clair County, IL (this county) | 2.03% | $3,665 | $180,300 |
| Madison County, IL | 1.92% | $3,319 | $173,000 |
| Washington County, IL | 1.87% | $2,908 | $155,700 |
| Clinton County, IL | 1.83% | $3,524 | $192,400 |
| Monroe County, IL | 1.63% | $4,588 | $282,100 |
| Randolph County, IL | 1.43% | $1,927 | $135,100 |
| St. Louis County, MO | 1.2% | $3,335 | $276,800 |
| St. Louis city, MO | 1.03% | $2,033 | $197,500 |
How is a home assessed in St. Clair County?
Illinois assesses homes at 33.33% of market value in every county, St. Clair County included. How Illinois assesses and reappraises homes.
Is there a homestead exemption in St. Clair County?
Yes. Illinois's General Homestead Exemption is $6,000 of equalized assessed value in most counties, $8,000 in counties next to Cook, and $10,000 in Cook County. That is the Illinois rule, and it applies in St. Clair County. Illinois's exemptions and relief programs in full.
St. Clair County does not add relief programs of its own beyond the Illinois ones (checked September 23, 2026).
How to appeal your St. Clair County property assessment
In St. Clair County you appeal to the St. Clair County Board of Review. The deadline: File with the Board of Review within 30 days after your township's assessment list is published in the local newspaper, so the deadline depends on your township. For the 2026 assessments (taxes payable in 2027) the last day to file is September 25, 2026 in Lebanon and Shiloh Valley townships; September 29, 2026 in Belleville, Lenzburg, Marissa, Millstadt, St. Clair, Stookey and Sugarloaf townships; and September 28, 2026 in Caseyville, Centreville, East St. Louis, Engelmann, Fayetteville, Freeburg, Mascoutah, New Athens, Prairie Du Long, Smithton and Stites townships. Canteen and O'Fallon township values had not been published as of September 23, 2026; owners there have 30 days from their township's publication date, so check with the Assessor for the exact day. A township is not the same as the city of the same name, so check which township your parcel is in. Start with an informal review at the County Assessor's office. All evidence must reach the Board of Review at least 5 days before your hearing. A Board of Review decision can be appealed to the Illinois Property Tax Appeal Board within 30 days of the written decision. How to file. Checked September 23, 2026 against the official appeal rules.
How Illinois's appeal process works, including the next level if the first one turns you down.
Illinois rules from primary state sources, reviewed September 7, 2026; sources on the Illinois page.
Work out your own numbers
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How much house can I afford?
Your income, debts and down payment against the 28/36 rule lenders actually use, with St. Clair County's tax rate to hand.
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Mortgage calculator
Monthly payment with principal, interest, tax and insurance, plus what an extra payment saves you.
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Illinois income tax
Brackets, standard deduction and what Illinois actually taxes.
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Sales tax in St. Clair County
The other local tax: combined state and local rate for this county.
Sources
- Median real estate taxes paid and median home value for St. Clair County, Illinois: U.S. Census Bureau, American Community Survey 5-year estimates (2020-2024), tables B25103, B25077, B25102, B25119 and B25003; the five-year comparison uses the 2015-2019 estimates. Neighboring counties: Census county adjacency file.