St. Clair County Property Tax Guide: Pay, Search, Due Dates & Exemptions
St. Clair County property tax questions usually involve more than one office. The Treasurer mails real estate tax bills, collects payments and manages tax sale timing. The Assessor handles assessments, property records, many exemptions and parcel or mobile-home details.
Use this guide to pay the right tax bill, search real estate or mobile home taxes, understand 2026 due dates, avoid publication or tax sale, review exemptions, prepare appeal evidence, and contact the correct St. Clair County office before a deadline passes.
Quick Answer: Where to Start
To pay or view St. Clair County property tax bills, start with the St. Clair County Treasurer or the official property tax inquiry portal. You can search real estate and mobile home tax bills before paying.
To correct assessed value, property details, exemptions, parcel records or mobile home assessment questions, start with the St. Clair County Assessor. To formally appeal an assessment, use the St. Clair County Board of Review process.
Fast Route: Choose the Right St. Clair County Office
Use this routing table before opening a portal. It helps prevent the most common mistake: contacting the payment office for an assessment issue, or contacting the Assessor for a receipt issue.
| Your Task | Start Here | Why | Best Next Step |
|---|---|---|---|
| Pay current real estate tax | Treasurer | The Treasurer collects property tax payments. | Open the official real estate and mobile home inquiry portal. |
| Search amount due | Treasurer inquiry | Tax bills, balances and payment status are collection records. | Search by PIN, mobile home number, owner name or site address. |
| Change assessed value | Assessor / Board of Review | The Treasurer cannot reduce the assessed value. | Talk with the Assessor, then file Board of Review complaint if needed. |
| Apply for exemption | Assessor or Board of Review | Different exemptions are administered through assessment offices. | Use the current PTAX form or county application. |
| Taxes were sold | County Clerk / Treasurer guidance | Sold taxes and redemption require a different process from normal payment. | Use tax redemption search or call the correct county office quickly. |
St. Clair County Property Tax Due Dates
St. Clair County’s 2025 real estate taxes payable in 2026 are collected in two installments. The Treasurer’s official collection page says all dates are tentative until further notice, so verify the county page before paying near a deadline.
| Date | Official Meaning | What You Should Do |
|---|---|---|
| May 26, 2026 | Tax bills mailed. | Search online if you do not receive the bill or need the PIN. |
| July 1, 2026 | First installment due date. | Pay the first half or full bill before this date. |
| September 1, 2026 | Second installment due date. | Pay remaining balance before late penalties increase. |
| September 18, 2026 | Last day to avoid publication. | Do not rely on postmark; electronic payments stop at 3 PM on this deadline. |
| September 25, 2026 | Certified notices mailed. | Act immediately if you receive one. |
| September 28–October 2, 2026 | Newspaper publication period. | Pay before publication deadlines if possible. |
| October 30, 2026 | Last day to pay to avoid tax sale. | Pay in the Treasurer’s office by 4:30 PM; electronic payments stop at 3 PM. |
| November 2, 2026 | Tax sale date. | Contact the county before this date if unpaid taxes remain. |
Deadline warning: On publication and tax-sale deadlines, the Treasurer states postmark is not accepted and electronic payments shut down at 3 PM. Pay early if you are close to a deadline.
How to Pay St. Clair County Property Taxes
You may pay St. Clair County real estate taxes online, by mail, at the Treasurer’s office, or at many local financial institutions during the allowed collection period. The Treasurer states local financial institutions can accept real estate tax payments only through the second due date.
Online credit card, debit card and e-check payments are processed through the payment portal. The Treasurer says credit card transactions are charged 2.5% or a $2.00 minimum, and e-check transactions are charged $1.50 up to $50,000.
- Open the St. Clair County property tax inquiry portal.
- Search by parcel number, mobile home number, owner name or site address.
- Confirm the tax year, PIN, owner name, site address and amount due.
- Choose the correct installment or balance.
- Review convenience fee before submitting payment.
- Save the confirmation and receipt.
Payment safety: If the portal does not show the correct parcel, owner, site address or tax year, stop before paying. Use the Treasurer or Assessor contact route to verify the record.
Online, Mail, Office and Bank Payment Options
The payment method matters near deadlines. Local financial institutions have cutoff limits, electronic systems shut down at specific times near tax sale deadlines, and postmarks may not count for certain final deadlines.
| Payment Route | How It Works | What to Watch |
|---|---|---|
| Online | Use the official portal and follow payment links after searching the parcel. | Convenience fees apply; final-deadline electronic cutoff may be 3 PM. |
| Telephone | Phone payment may be available through the payment system listed by the Treasurer. | Telephone system may shut down with online payments near final deadlines. |
| Mail payment with the correct parcel and installment details. | Postmark is not accepted for some final publication or tax-sale deadlines. | |
| Treasurer office | Pay in person at the Treasurer’s office during collection hours. | Bring bill, PIN, ID if needed, and accepted payment method. |
| Financial institutions | Some local banks may accept real estate tax payments during the allowed period. | They can accept real estate tax payments only through the second due date. |
How to Search St. Clair County Property Tax Bills
The official tax inquiry portal can search real estate and mobile home tax records. Search carefully, because name and address entries can be abbreviated or formatted differently from your deed or mailing address.
The portal allows searches by parcel number, mobile home number, owner name as listed on the tax bill, or site address criteria. Use parcel number when you have it.
- Open the St. Clair County Property Tax Inquiry page.
- Search by parcel number if available.
- Use owner name or site address only if you do not know the parcel number.
- Confirm the year, location, owner and tax balance.
- Check whether the record is real estate or mobile home before paying.
How St. Clair County Property Taxes Are Calculated
The Treasurer explains that your bill is for services provided by taxing districts listed on the front of the bill. The Assessor sets assessment on land and buildings, using prior sale figures as required by Illinois law.
Exemptions are subtracted from local value to create taxable value. Then taxable value is multiplied by the tax rate, which is the sum of rates from the taxing bodies shown on your bill.
| Bill Line | Plain Meaning | Who to Contact |
|---|---|---|
| Local value | Assessment value set for land and building. | Assessor |
| Exemptions | Approved reductions applied before taxable value is calculated. | Assessor or Board of Review, depending on exemption. |
| Taxable value | Local value after approved exemptions. | Assessor for value/exemption; Treasurer for bill collection. |
| Tax rate | Combined rate from taxing bodies on the bill. | County Clerk or taxing district for rate/levy questions. |
| Total tax due | Amount payable for the installment or full bill. | Treasurer |
Treasurer vs Assessor vs Board of Review vs County Clerk
St. Clair County property tax work is split between offices. Use the correct office for the specific problem.
| Office | Main Role | Use This Office For |
|---|---|---|
| Treasurer | Mails tax bills, collects payments, distributes tax revenue and administers tax-sale collection steps. | Paying taxes, receipts, balances, partial payments, monthly plan, sold tax guidance. |
| Assessor | Determines assessments and maintains many property, mobile home and exemption records. | Assessed value, property record card, general homestead, disabled/veteran exemptions, mobile home records. |
| Board of Review | Hears assessment complaints and some exemption matters. | Assessment appeal, complaint forms, hearing evidence and written decision. |
| County Clerk | Calculates tax rates and handles tax redemption information after taxes are sold. | Tax rates, redemption search and some delinquent-tax post-sale questions. |
St. Clair County Property Tax Exemptions
Exemptions reduce taxable value only if the property and owner qualify and the correct application is approved. Do not assume an exemption appears automatically just because you live in the home.
The Assessor’s documents page includes General Homestead, Senior Homestead, Senior Freeze, Disabled Persons, Disabled Veterans, Returning Veterans and other PTAX forms. Some exemption questions may route to the Board of Review.
| Exemption or Form | Who It May Help | Where to Start |
|---|---|---|
| General Homestead / Owner Occupied | Homeowners who own and occupy the property as their principal residence. | Assessor homestead application and customer service team. |
| Senior Citizens Homestead | Owner-occupied residence of a person 65 or older during the tax year. | Board of Review or senior exemption route listed by county. |
| Senior Assessment Freeze | Seniors meeting ownership, residence and income requirements. | Assessor or PTAX-340 current-year form. |
| Persons with Disabilities | Qualifying disabled homeowners. | Assessor PTAX-343 initial or renewal forms. |
| Disabled Veterans | Qualifying veterans with disabilities or eligible surviving spouses. | Assessor PTAX-342 initial or renewal forms. |
| Returning Veterans | Qualifying veterans returning from active duty in an armed conflict. | Assessor PTAX-341 form. |
| Non-homestead exemption | Some charitable, religious, hospital, fraternal or organizational property uses. | Board of Review PTAX-300 series forms. |
- Search your property tax record and property record card.
- Check which exemptions are already applied.
- Open the Assessor or Board of Review forms page.
- Use the current-year form where required.
- Submit supporting documents and keep confirmation.
Senior Citizen Tax Programs and Exemptions
St. Clair County’s senior page lists several senior-related tax relief options. The Senior Citizens Homestead Exemption reduces assessed value by $5,000 for a residence owned and occupied by a person 65 or older during the tax year.
The Senior Citizens Assessment Freeze may freeze assessed value for seniors who meet ownership, principal-residence and income requirements. The county page lists a $75,000 household income limit for this program.
| Program | Main Rule | Action Step |
|---|---|---|
| Senior Homestead | For qualifying owner-occupied residence of a person 65 or older. | Contact Board of Review if it is missing. |
| Senior Assessment Freeze | For qualifying seniors with household income at or below the county-stated limit. | Contact Assessor at 618-825-2704 for application guidance. |
| Senior Tax Deferral | May allow qualifying seniors to defer all or part of real estate taxes and special assessments. | Contact Treasurer at 618-825-2440 for request forms. |
| Email reminders | Helps seniors and other taxpayers avoid late penalties and sold taxes. | Use the Treasurer’s reminder options if available. |
How to Appeal a St. Clair County Property Assessment
If the assessed value appears wrong, begin with an informal discussion and review with the County Assessor’s office. Many cases are resolved before a formal hearing.
If the issue is not resolved, you may file an appeal with the elected three-member Board of Review. After filing, you receive written notice of your scheduled appointment and may present evidence.
- Search your property and get the property record card.
- Compare your assessment with similar properties in your neighborhood.
- Speak with the Assessor before filing a formal complaint.
- Download the current Board of Review complaint form.
- Gather evidence and submit it before the hearing deadline.
- Attend the scheduled hearing and wait for the written decision.
| Evidence Type | Best For | How to Use It |
|---|---|---|
| Exterior photo | Showing condition or property type. | Bring photo of your home or business. |
| Three comparable properties | Showing similar neighborhood properties assessed lower. | Use comparable property record cards and photos. |
| Property record card | Finding wrong square footage, class, features or assessment comparison. | Mark the incorrect or unequal details. |
| Recent appraisal | Supporting a market value argument. | Use a credible appraisal tied to the relevant assessment period. |
| Sales contract, settlement statement or deed | Recent buyer or sale-price evidence. | Show arm’s-length sale date and price if available. |
Board of Review evidence deadline: The county Board of Review page says all evidence must be in the Board of Review office at least 5 days before the scheduled hearing, or the appeal may be upheld with no change.
After the Board of Review Decision
The Board of Review hears your case, reviews evidence, rules on the appeal, and sends a written decision. If you still disagree after receiving the decision, the county Treasurer’s tax appeals page points to the Illinois Property Tax Appeal Board as a possible next appeal route.
Post-decision appeals can be deadline-sensitive. Review the written decision carefully and get professional help if the property is commercial, high-value, estate-owned, in foreclosure, or already near tax sale.
Partial Payments and Monthly Payment Plan
St. Clair County allows partial payments, but partial payments do not erase penalties on late balances. The Treasurer’s partial payment page states Illinois imposes a 1.5% monthly penalty on unpaid late balances.
The Treasurer also offers a monthly payment plan to help taxpayers budget for next year’s tax bill. The FAQ says the plan is open to homeowners when taxes are current and the property has the Homeowner Occupied Exemption applied.
| Option | What It Does | Important Limit |
|---|---|---|
| Partial payment | Lets you pay part of the amount due. | Late unpaid balances may still accrue monthly penalty. |
| Monthly payment plan | Helps budget toward next year’s bill. | Does not extend or change statutory due dates. |
| Automatic withdrawal | May allow planned payments from a bank account. | Use official Treasurer forms and confirm enrollment timing. |
| Tax sale deadline | Final deadline to prevent sale of delinquent taxes. | All balances must be paid by the county’s final deadline. |
If Your St. Clair County Taxes Were Sold
When real estate taxes remain unpaid through the final collection period, the county may sell the taxes at tax sale. This does not mean you should wait; deadlines and redemption costs can become more serious quickly.
If your taxes were sold, use the official county guidance and tax redemption search instead of the normal payment route. Amounts may need to be searched through the County Clerk tax redemption process or confirmed by phone.
- Find the parcel number and tax year.
- Use the county tax redemption search route if available.
- Contact the County Clerk or listed office for redemption amount.
- Ask which payment forms are accepted for redemption.
- Act quickly because redemption deadlines can affect ownership rights.
High-risk warning: Tax sale and redemption are legal/financial matters. Get official help immediately if a property is owner-occupied, estate-owned, mortgaged, in bankruptcy, or already subject to legal notices.
Mobile Home Taxes and Mobile Home Search
St. Clair County’s tax inquiry portal includes a mobile home number search. The Assessor also lists mobile home registration and related forms.
Use the mobile home number when it appears on your bill or county documents. If the record is missing, ownership changed, or the mobile home details look wrong, contact the Assessor’s mobile home department before paying the wrong record.
| Mobile Home Issue | Start Here | What to Prepare |
|---|---|---|
| Pay mobile home tax | Tax inquiry portal | Mobile home number, owner name or site details. |
| Wrong owner or location | Assessor mobile home contact | Title, bill of sale, address and registration documents. |
| Need registration form | Assessor documents and forms | Current owner and location information. |
| Privilege tax reduction | Assessor documents and forms | Application and eligibility proof if applicable. |
Address Change, Missing Bill and Receipt Problems
Not receiving a tax bill does not remove the responsibility to pay on time. If the mailing address is wrong, fix the address and search online for the current bill.
For payment receipts, start with the Treasurer’s office or online payment confirmation. For assessment mailing details, property records or owner-related data, start with the Assessor.
Search the tax inquiry portal and verify your mailing address before the due date.
Use Assessor contact routes and bring deed or recorded document support if needed.
Use Treasurer payment records or confirmation details from the portal.
Verify payment posting even if your lender says taxes were paid from escrow.
St. Clair County Property Tax Office Contacts
Bring your parcel number, bill, tax year, owner name, site address, payment confirmation and any exemption or appeal documents when contacting an office.
| Office | Contact | Use For |
|---|---|---|
| Treasurer | 10 Public Square, Belleville, IL 62220 Phone: 618-825-2707 Email: treasurer@co.st-clair.il.us | Tax bills, payments, receipts, due dates, partial payments and tax sale collection. |
| Assessor | 10 Public Square, Belleville, IL 62220 Phone: 618-825-2704 Email: assessor@co.st-clair.il.us | Assessment, property record cards, exemptions, mobile home and parcel records. |
| Homestead Exemptions | Phone: 618-825-2704 Email: homesteadexemptions@co.st-clair.il.us | General Homestead, veterans, disabled persons and returning veterans exemption questions. |
| Board of Review | 10 Public Square, Belleville, IL 62220 Phone: 618-825-2489 Email: boardreview@co.st-clair.il.us | Assessment complaints, hearings, evidence and written appeal decisions. |
Common St. Clair County Property Tax Mistakes
Most payment, exemption and appeal problems are preventable if you check the tax year, parcel number, office role and deadline before submitting anything.
Electronic payments and postmarks have strict final-deadline limits. Pay earlier.
The Treasurer collects taxes. Assessment value starts with the Assessor and Board of Review.
Board of Review evidence must be submitted before the scheduled hearing deadline.
Many exemptions require application, proof, renewal or current-year forms.
Check PIN, owner, address, year and installment before payment.
Even escrowed owners should confirm the lender payment posted to the correct parcel.
Related Property Tax Guides on This Site
These internal guides can help you understand the wider property tax process before using official St. Clair County systems.
Official St. Clair County Property Tax Links
Use these official links when you are ready to pay, search, apply, appeal, check a deadline, or verify account-specific information.
St. Clair County Property Tax FAQs
Which St. Clair County is this guide for?
This guide is for St. Clair County, Illinois. If you need Alabama, Michigan, Missouri or another St. Clair County, use that county’s official treasurer or revenue office instead.
Where do I pay St. Clair County Illinois property taxes?
Use the St. Clair County Treasurer or the official real estate and mobile home tax inquiry portal. You can pay online after confirming the parcel or mobile home record.
Can I search St. Clair County property taxes online?
Yes. The official tax inquiry portal lets users search by parcel number, mobile home number, owner name as listed on the tax bill, or site address criteria.
When are St. Clair County property taxes due in 2026?
For 2025 real estate taxes payable in 2026, the Treasurer lists the first installment due July 1, 2026 and the second installment due September 1, 2026.
When is the last day to pay before tax sale?
The Treasurer lists October 30, 2026 as the last day to pay to avoid tax sale, with the tax sale scheduled for November 2, 2026.
Do postmarks count on the last day to avoid publication or tax sale?
The Treasurer’s collection-date page says postmark will not be accepted for those final deadlines, and electronic payments stop at 3 PM on those dates.
Can I pay St. Clair County taxes by credit card?
Yes, online credit card, debit card and e-check payments are available through the portal. The Treasurer states credit card transactions have a 2.5% fee or $2.00 minimum, and e-checks cost $1.50 up to $50,000.
Can I pay at a local bank?
The Treasurer says many local financial institutions accept real estate tax payments, but only through the second due date.
Who handles exemptions?
The Assessor handles many homestead, disabled person, veteran and returning veteran exemptions. The Board of Review handles assessment complaints and some exemption matters.
What is the Senior Citizens Homestead Exemption?
St. Clair County states the Senior Citizens Homestead Exemption reduces assessed value by $5,000 for a residence owned and occupied by a person 65 or older during the tax year.
What is the Senior Assessment Freeze?
The Senior Assessment Freeze may freeze assessed value for qualifying seniors who own and use the property as their principal residence and meet income requirements listed by the county.
How do I appeal my St. Clair County assessment?
Start with an informal review with the Assessor. If unresolved, file a formal complaint with the St. Clair County Board of Review and submit evidence before the hearing deadline.
What evidence helps a Board of Review appeal?
Useful evidence includes exterior photos, three comparable properties, property record cards, recent appraisal, sales contract, settlement statement, deed or other proof supporting a lower assessment.
When must Board of Review evidence be submitted?
The Board of Review page says all evidence must be in the office at least 5 days before the scheduled hearing, or the appeal may be upheld with no change.
Who do I contact if taxes were sold?
Use the county’s sold-tax and redemption guidance. The County Clerk tax redemption route may be needed after taxes are sold.
Is CountyPropertyTaxes.us an official government website?
No. This is an independent guide. Use official St. Clair County Treasurer, Assessor, Board of Review, County Clerk and Illinois PTAB links for final account-specific actions.
Bottom Line
For St. Clair County property tax payments, use the Treasurer and official tax inquiry portal. For assessed value, exemptions, property record cards or mobile home assessment issues, use the Assessor. For formal value appeals, use the Board of Review and submit evidence before the hearing deadline.
Pay StepsSearch Tax BillsDue DatesExemption HelpAppeal StepsOfficial Links