Illinois property taxes are due in two installments each year, with the first half due June 1 and the second half due September 1

Illinois splits the property tax year into two payment periods. The first installment covers January through June and is due by June 1. The second installment covers July through December and is due by September 1. Both dates are firm — if you pay after these dates, you owe a penalty.

The exact amount you owe depends on your county assessor's valuation of your property and your local tax rates, which vary by school district, municipality, and special districts. You will receive a bill in the mail before each due date, usually several weeks in advance. The bill shows the amount due, where to send payment, and the penalty amount if you miss the important date.

If you own property in multiple Illinois counties, each county sends its own bill on its own schedule. You cannot combine payments or defer one to pay another. Missing either important date triggers a penalty that compounds monthly until you pay.

Key Takeaways

  • First installment property taxes are due June 1 each year; second installment is due September 1.
  • Payments made after the due date incur a penalty that increases each month the bill remains unpaid.
  • Your county assessor's office or your county treasurer's office can tell you the exact amount owed and accept payment by mail, online, or in person.
  • If you own property in more than one county, each county sends a separate bill with its own due date and penalty structure.
  • Property tax bills are mailed before each due date, but you are responsible for paying on time even if you do not receive the bill.

How penalties work if you miss the important date

Illinois charges a penalty of 1.5 percent per month on unpaid property taxes, starting the day after the due date. This means if you owe $1,000 and pay on July 1 (one month late on a June 1 bill), you owe $1,015. If you do not pay until August 1, you owe $1,030.23. The penalty compounds monthly, so the longer you wait, the more you pay.

After a property tax bill goes unpaid for a set period — usually around three years, though this varies by county — the county may file a tax deed action. This is a legal process that can result in the county or another buyer taking ownership of your property. You have the right to redeem the property by paying all back taxes plus costs, but the window to do so is limited and closes before the tax deed sale occurs.

If you cannot pay by the due date, contact your county treasurer's office when ready. Some counties offer payment plans or hardship deferrals, though these are not may provide and depend on your county's policies.

Where to send payment and accepted methods

Your county treasurer's office collects property taxes. The bill you receive shows the mailing address for checks or money orders. Most Illinois counties also accept online payment through their treasurer's website, which typically allows you to pay by bank transfer or credit card (though credit card payments may include a processing fee).

You can also pay in person at the treasurer's office during business hours. Bring your bill or property identification number (PIN) so the office can explore the payment to the correct property. Some counties accept payment at banks or through third-party payment processors, but the safest route is to pay directly through the county treasurer or the official county website.

If you use a mortgage servicer or property management company, they may handle tax payments on your behalf as part of an escrow account. In that case, you do not pay directly — the servicer pays the county. You should still receive a statement showing when the payment was made.

What happens if you own the property but did not receive a bill

Illinois law holds you responsible for paying property taxes on time even if you never receive a bill. If your address on file with the county assessor is incorrect, or if the bill is lost in the mail, you still owe the full amount plus penalties if you pay late.

To avoid this, verify your mailing address with your county assessor's office at the start of each tax year. You can also sign up for email reminders through your county treasurer's website if that option is available. Some counties offer online portals where you can view your bill before it arrives in the mail.

If you did not receive a bill and the due date has passed, contact your county treasurer when ready to find out what you owe and to arrange payment. Explain that you did not receive the bill — the treasurer cannot waive the penalty, but they can confirm the amount and help you avoid further penalties by paying right away.

Deferral and hardship options in some counties

A small number of Illinois counties offer property tax deferral programs for homeowners who are elderly, disabled, or facing financial hardship. These programs allow you to delay payment for a set period, though the taxes still accrue and must be paid eventually, usually when you sell the property or pass it to an heir.

Deferral is not automatic and is not available in all counties. You must file a request with your county assessor or treasurer before the tax bill becomes delinquent. The income and asset limits vary by county, and the process process can take several weeks.

Contact your county assessor's office to ask whether your county offers deferral and what the income limits are. If your county does not offer deferral, ask about payment plans or other options. Some counties will work with you on a schedule if you contact them before the due date.

Special assessments and other tax bills

In addition to regular property taxes, you may receive bills for special assessments — charges for local improvements like street repairs, water line upgrades, or drainage projects. These bills follow the same June 1 and September 1 schedule as regular property taxes and carry the same penalties if unpaid.

You may also receive a separate bill for municipal utilities tax if your municipality imposes one. This is a small tax on water, gas, or electric service and is usually billed separately from property taxes, though some municipalities include it on the property tax bill.

Read every bill you receive carefully to understand what it covers. If you are unsure whether a bill is legitimate, contact your county treasurer or municipality before paying.

Frequently Asked Questions

What if I pay one installment but not the other?

Both installments are separate bills with separate due dates. If you pay the first installment by June 1 but miss the September 1 important date on the second, you owe a penalty only on the second installment. The penalty applies to whichever bill is unpaid, not to the whole year's taxes.

Can I pay property taxes online in Illinois?

Most Illinois counties accept online payment through their treasurer's website. Go to your county treasurer's office website and look for a "pay taxes online" or "make a payment" link. You will need your property identification number (PIN) or bill number. Some counties charge a small processing fee for credit card payments.

What is the property identification number and where do I find it?

The PIN is a unique number assigned to your property by the county assessor. It appears on your property tax bill, your property assessment notice, and the county assessor's website. You can also call your county assessor's office and provide your address to get the PIN.

Do I have to pay property taxes if I am behind on my mortgage?

Yes. Property taxes and mortgage payments are separate obligations. If your mortgage servicer pays your taxes through an escrow account, the servicer handles it. If you pay taxes directly, you must pay them on time even if you are behind on the mortgage. Unpaid property taxes can lead to tax deed sale, which can happen even if you are current on your mortgage.

What happens if I pay late but before the tax deed sale?

You can pay at any time before the tax deed sale occurs. When you pay, you owe all back taxes plus penalties and the county's costs for the collection process. The exact costs depend on how long the bill has been unpaid and what collection steps the county has taken. Contact your county treasurer to find out the total amount due.