Frequently asked questions
Common questions about Cook County property tax appeals — deadlines, how filing works, and how NeighborComp fits in.
Free guides & getting started
Is there a free guide before I buy anything?
Yes. Our free Cook County Property Tax Appeal Basics guide explains how assessments work, where to appeal, what evidence helps, and the basic filing steps. You can read it online or download the PDF.
Can I get a simple filing checklist?
Yes. The free checklist helps you gather your PIN, property details, comparable-home evidence, deadline, official filing link, and confirmation details before you begin.
About NeighborComp
Is NeighborComp a government office?
No. NeighborComp is a private company and is not affiliated with the Cook County Assessor, Board of Review, or any government office. We provide information and a do-it-yourself kit — we do not file appeals for you and we do not give legal advice.
Do I need a lawyer to file a Cook County tax appeal?
No. Homeowners can file their own appeals online for free on the official websites. Our kit simply organizes your evidence and tells you exactly what to type where.
How do you decide if my home is over-assessed?
We compare your home's assessed value per square foot with similar homes — same neighborhood, similar size and age — using public Cook County assessment records. If your home's per-square-foot assessed value is meaningfully higher than comparable homes, that suggests an appeal is worth filing.
Is the check really free?
Yes. Enter your address or 14-digit property PIN and see your verdict in seconds. If your assessment looks in line, we'll tell you that too — no kit needed.
Deadlines
When can I file an appeal?
Cook County appeals are open only during a filing window for your township — first with the Assessor's Office, and later (if needed) with the Board of Review. Each township gets its own dates each year, roughly 30 days at a time.
What happens if I miss my township's deadline?
You generally have to wait for the next office's window — the Board of Review opens later than the Assessor for each township — or file with the Illinois Property Tax Appeal Board (PTAB) after paying your bill. Missed windows can't be reopened, so it's worth checking your township's dates now.
Can I appeal with both the Assessor and the Board of Review?
Yes. They are separate appeals. If you're unhappy with the Assessor's decision, you can file with the Board of Review during your township's Board window — the deadlines page shows both.
Where do I find my township's exact dates?
Our deadlines page lists every township's current Assessor and Board of Review windows, with links to the official calendars. Always confirm on the official website before filing — dates can shift.
The filing process
How do I actually file an appeal?
For your township's Assessor window, file online on the Cook County Assessor's residential appeal form — you'll enter your PIN, your opinion of value, and comparable homes that support it. For the Board of Review, file online during your township's Board window. Our appeal guide walks through each step.
What evidence makes a strong appeal?
Comparable homes — similar nearby homes assessed at a lower per-square-foot value — plus recent sale prices of similar homes. That's exactly what our free check and the kit generate for you.
What do I enter in the online appeal form?
Your PIN, your opinion of your home's market value, and the PINs (and values) of comparable homes. The kit includes a worksheet listing every value to type in, so you don't have to dig for anything.
How long does a decision take?
It varies by office and season — the Assessor typically issues decisions in the weeks after a township's window closes, and the Board of Review later. Your new assessment shows up on your second-installment property tax bill.
Does filing an appeal raise my taxes?
No. An appeal asks the office to lower your assessment to match similar homes. Assessments can only go down as a result of an appeal you file — not up.
Will an appeal lower this year's bill?
Appeals lower your assessed value, which reduces your tax bill — typically reflected in the following year's second-installment bill, depending on when the decision lands.
The kit, refunds & your order
What's in the $79 kit?
A PDF with your comparable homes, recent nearby sales, a plain-English argument, a filing worksheet of every value to type into the online appeal form, step-by-step instructions with official links and your deadline, plus a personal step-by-step appeal walkthrough online.
What if my appeal doesn't lower my assessment?
Request a refund within 12 months of purchase and upload your decision letter. We review and refund eligible requests — see the refund page.
How do I get my kit again or check my refund?
Use the order lookup page with your order number and checkout email. No account needed.
Are the savings guaranteed?
No. Savings shown are estimates only. The assessing offices decide every appeal.
How will I know when my township's window opens?
Each buyer whose township window opens gets a reminder email if they've joined our newsletter, with a direct link to their appeal steps.
More questions? Email support@neighborcomp.com. See also the appeal guide, deadlines, and order lookup.