Know your case before you pay anyone.
How your Cook County assessment becomes a tax bill, the two free appeal windows, the exemptions most people forget to check, and what to verify before signing anything.
Your tax bill is three numbers. You can only fight two of them.
Assessed value
The Assessor estimates what your home is worth, on a three-year reassessment cycle. This is the number an appeal challenges — if it's too high relative to similar homes or the market, you have a case.
Exemptions
Homeowner, senior, and other exemptions subtract from your taxable value. They are free to file, and a missing one quietly costs you money every single year until someone catches it.
Tax rate
Schools, parks, and local government set levies that become your rate. No appeal touches this number — which is why the assessment and the exemptions are where the real leverage lives.
A "no" from the Assessor is not the end.
Opens township by township through the year. File when your township opens, with evidence that your assessed value is out of line. Free to file.
A separate agency with its own later window. You can file here even if the Assessor said no change — and even if you never filed with the Assessor at all. Also free to file.
Deadlines are township-specific and unforgiving — a strong case filed a day late is worth nothing. Check your township before doing anything else.
The five-minute pre-check.
Is your window open?
Appeals only count inside your township's window. If it's closed, your move is the next stage or next year — not a rushed filing or a panic purchase.
Is your record right?
Wrong square footage, class, or property characteristics in the county record can inflate an assessment by themselves. Record errors are some of the cleanest cases there are.
Do the comps back you?
The strongest argument is usually uniformity: similar homes nearby assessed for less than yours. Feeling overtaxed is not evidence — comparable properties are.
What would you pay?
You can file yourself for free, buy flat-fee evidence support, or sign over a percentage of savings to a firm. Know which deal you're taking before anyone has your signature.
Sometimes the right answer is "don't."
- If your home is already assessed in line with comparable properties, an appeal has little to work with — no matter how high the bill feels.
- If the possible savings are small, paying someone a percentage of them rarely makes sense. File yourself for free, or let it go this year.
- If your window is closed, nothing useful happens until the next stage or next cycle. Set a reminder instead of paying for urgency.
That's the point of checking first: a free lookup tells you whether the numbers support acting at all, before anyone — including Censum — asks you to spend money.
The questions every Cook County homeowner asks.
Does it cost anything to appeal a Cook County assessment?
No. Filing an appeal with the Cook County Assessor or the Board of Review is free, and the county forms are free. You only pay if you choose paid help, such as flat-fee evidence support or a percentage-of-savings firm.
Can I appeal my tax rate or my tax bill directly?
No. The tax rate comes from local government levies and is not appealable. What you can contest is your property's assessed value, and you can make sure every exemption you qualify for is applied.
What if the Assessor denies my appeal or I miss the window?
The Board of Review is a separate second window later in the cycle. You can file there even if the Assessor said no change, and even if you never filed with the Assessor at all.
How often is my Cook County property reassessed?
Cook County reassesses on a three-year cycle, rotating through the City of Chicago, the north suburbs, and the south and west suburbs. You can still appeal in non-reassessment years.
When is the appeal deadline for my township?
Deadlines open and close township by township throughout the year. Check the current official calendar for your township before spending time on evidence.
Who is this page for?
Homeowners staring at a reassessment notice, anyone weighing a percentage-of-savings agreement, and advisors or neighbors who need an educational link that explains the process without promising an outcome.
One lookup answers most of this page for your address.
Your historical win rate, possible savings, and the best next step for your specific property — free, with no email, phone, or signup required to see the result.
Censum is independent and not affiliated with Cook County or any government agency. Censum is not a law firm and does not guarantee savings or appeal outcomes. Odds are calibrated from real Cook appeal outcomes — not guarantees.