How to appeal your property taxes in Cook County yourself
To appeal a Cook County property tax assessment yourself you file, inside your township’s window, evidence that near-identical homes nearby are assessed lower than yours — and the free check on this page tells you in a few seconds whether yours are. If they are, the $59 Tax Appeal Evidence Packet assembles what a tax agent or attorney would otherwise put together: your township’s deadline and next step, the comparable homes and recent sales, your parcel’s own appeal history, and an appeal statement ready to paste into the form. You file it; we take no share of the saving.
Most Cook County residential appellants don’t file alone: in tax year 2026, 71,931 of 95,204 used an agent or attorney, who is typically paid a share of the first year’s saving rather than a fee up front. About 23,273 filed for themselves. This packet is for them — if you’d rather someone else did the filing and the arguing, use an agent; that is a real option and often a sensible one.
Build your packet
- Check your home by address or 14-digit PIN (free).
- See your case strength. The packet is offered for a Moderate or Strong case, or a recent purchase that supports an appeal.
- Review your packet and go to checkout.
Live now: confirms your PIN, shows your assessed values for 2023–2026 and a case-strength estimate for houses and condo units, with your township’s appeal dates where they have been checked. The packet is offered while your township has a checked appeal window open; the check tells you if it does.
Deadlines are set by township. Cook County reassesses one region a year and opens appeal windows township by township. The packet shows your township’s Assessor and Board of Review windows as published, with the date they were checked and how many days are left, and it isn’t produced once both have closed. Meanwhile, check your township’s appeal window free, see how much assessments moved around you at the latest reassessment, or see your township’s reassessment and how its appeals ended.
What a Cook County property tax appeal needs, and which half is free
Free Assessment Check · $0
Live now
- Your parcel confirmed by PIN, from the Assessor’s address file
- Your assessed values for 2023–2026: Assessor mailed, certified and Board of Review
- Estimated result for homes: Strong, Moderate, Weak or No case found, from your assessed value per sq ft against the median of near-identical homes, with the appeal outcomes measured at each level (method and evidence)
- Estimated result for condo units: your building’s assessments compared with its own recent sales, against other buildings in your neighborhood, where there are enough sales (method and evidence)
- For houses bought since 1 January two years before the tax year: whether your purchase price, recorded as an ordinary sale and in line with what similar homes nearby sold for, is at least 10% below the Assessor’s market value
Coming, not available yet
- The same result for multi-building parcels, and for condo buildings without enough recent sales
- Reminder emails before a window closes, if you opt in
Evidence Packet · $59
- Your township’s Assessor and Board of Review windows, today’s status and days left, and the next step to take
- An appeal statement ready to paste into the appeal form, using only figures printed in the packet, and the value to ask for
- If your recent purchase supports an appeal: the sale set out as the evidence, the similar-home sales that back its price, the value at your purchase price, and the documents the Board of Review asks for with a sale (its Rule 18)
- The closest comparable homes (up to 8): address, PIN, size, age, beds, baths and assessed value; the median uses every match. Condo units get their building’s sales and comparable buildings instead
- Recent arm’s-length sales of similar homes, where they exist
- The dollar gap in assessed value, labelled as an estimate, and how it turns into a tax saving using the figures on your own bill
- Your PIN’s own Assessor and Board of Review appeal history
- What to have ready, where to file (free), and the Board of Review as the next step
- Every dataset cited with its capture date
Not included: the tax saving worked out for you (rates and exemptions depend on your bill, so the packet gives the calculation with your bill’s figures) and screenshots of the filing websites. No packet is produced for a township whose windows have both closed.
Evidence you can file, in a fixed order
Every packet opens with the answer, then what to do and by when, then the evidence. It always closes with what it doesn’t cover and the official sources behind it.
The packet is built from the same Cook County records as the free check, so the two always agree. We show its structure and data sources here rather than someone’s real property; you can also read a full sample packet.
How each fact will be marked
- Sourced · value taken from a named dataset and record
- Not published by source · the publisher doesn’t record this
- Could not be read · the record exists but a value failed strict checks
- Not checked · outside what this report covers
- The answerHow your assessed value per sq ft compares with the median of near-identical homes.
- Your appeal deadlineYour township’s windows, today’s status and the next step.Appeal calendar (Assessor and Board of Review, checked against the published pages)
- Comparable homes5–8 homes matched on class, size, age and location.uzyt-m557 · x54s-btds · 3r7i-mrz4 · 3723-97qp
- Sales evidenceRecent arm’s-length sales, where they exist.wvhk-k5uv
- Appeal historyPrior appeal outcomes for the parcel.y282-6ig3 · 7pny-nedm
- Filing it yourselfWhat to have ready, your appeal statement, where to file and what a reduction could save.
- What this report doesn’t coverNot legal representation; we don’t file for you. Estimates aren’t guaranteed reductions.
- Official sources and capture datesEvery dataset, with a link to the Assessor’s own lookup.
- You choose
- Your Cook County home, confirmed by address or 14-digit PIN
- Sold when
- Your check shows a Moderate or Strong case, or a recent purchase that supports an appeal, and your township’s appeal dates have been checked and a window is still open. The check tells you which applies to your home.
- Delivery
- Emailed within 2 business days
- Refund
- Automatic if the report can’t be generated
- For
- Owners filing their own appeal — about 23,273 of Cook County’s 95,204 residential appellants in tax year 2026
- Not for
- Commercial or mixed-use property, or anyone wanting us to file for them; if you use an agent, they assemble this themselves
See a sample report · a real report from public records, with identifying details masked
How ordering works
- Check your home in the Assessment Check at the top of this page, by address or 14-digit PIN.
- See your case strength. The packet is offered when it’s Moderate or Strong, or when your recent purchase supports an appeal.
- Review your packet summary and continue to secure checkout. You file the appeal yourself; we don’t file for you and take no share of any saving.
- We build and check the packet against the Assessor’s records and email it within 2 business days.
Built on free public records, and linked back to them
The Cook County Assessor publishes assessed values, home characteristics and sales as open data and runs its own property search; the Board of Review publishes its decisions. CivicDelta selects the comparable homes, does the arithmetic and shows its working. Read how the case-strength estimate was tested against 180,609 appeal outcomes, or the ten datasets behind this page.
Your township’s reassessment year and appeal outcomes · Chicago permit history for the same property · where this report works
Questions people ask before they appeal
Can I appeal my Cook County property taxes myself?
Yes. The Assessor and the Board of Review both accept an appeal filed by the owner, free of charge, and most of the work is assembling comparable homes. In tax year 2026, 23,273 of the 95,204 residential parcels appealed were filed without an agent or attorney.
Should I just use a tax appeal agent instead?
Many owners do: 71,931 of those 95,204 residential appellants in tax year 2026 were represented. An agent files for you and is usually paid out of the first year’s saving, so there is nothing to pay up front, and for a complex property that is often the better route. This packet is for the owner who intends to file themselves, at a flat $59, keeping the whole saving.
When is the Cook County appeal deadline for my township?
Cook County reassesses one region a year and opens appeal windows township by township, each open for roughly 30 days. The free check shows your township’s Assessor and Board of Review windows with the date we verified them and how many days are left; the township pages list them all.
What evidence do I need to appeal an assessment?
Usually comparable homes: near-identical properties in your township and neighborhood assessed at a lower value per square foot than yours, plus recent arm’s-length sales where they exist. If you bought your home recently in an ordinary sale for less than the Assessor’s market value, your purchase price is evidence too: the Board of Review asks for the closing statement, the buyer’s and seller’s names and any relationship between them, and, when the price is well below the assessed value, an affidavit describing the sale. The packet lists up to eight comparable homes with address, PIN, size, age, beds, baths and assessed value, and states the median across every match.
Do you file the appeal for me?
No. The packet gives you the evidence, your deadline, an appeal statement to paste into the form and what to have ready; you file it yourself, free, with the Assessor. CivicDelta is not a law firm or a tax representative and takes no share of any reduction.
What if the free check says my case is weak?
It says so plainly and the packet is not offered. A weak result means your assessed value per square foot is at or close to the median for near-identical homes, which is the evidence an appeal would otherwise rest on.
Which properties are covered?
Cook County residential houses and condominium units with enough comparable homes or recent building sales. Parcels with more than one building, mixed-use and commercial property are not rated, and the check tells you so rather than guessing.
Does the packet guarantee a reduction?
No. The figures are estimates from public records, and reductions also follow corrected characteristics, vacancy or other evidence. Nothing here is legal or tax advice, and CivicDelta is not affiliated with the Cook County Assessor or the Board of Review.
The other free tools
- Cook County appeal deadline checker — Is your township’s appeal window still open?
- Neighborhood assessment change — How far assessments moved around your home
- Chicago Permit Lookup — Permits and violations Chicago holds for an address
- Environmental Snapshot — EPA-regulated facilities within half a mile
- Nursing home lookup and compare — Ratings, staffing and citations, three homes compared
- Nursing home owner network — Every other home the same owner runs
- Doctor payments lookup — What companies reported paying a clinician
- California contractor checks — Does this license cover your job?