COOK COUNTY, FOR LAW FIRMSKnow which homes will win before the township opens

On the 2025 roll, homes on our list won 71.5% of attorney-filed Board of Review appeals. Every other home won 47.8%. We read the Assessor's roll for every township, rank each home against the homes the Assessor itself treats as its comparables, and sell the ranked list to property tax firms.

Flagged homes won

71.5%

9,272 attorney appeals, 2025

Every other home

47.8%

121,970 attorney appeals, 2025

Average cut per appeal

$6,419

against $1,921 for other homes

Never appealed

44,366

of 57,542 flagged homes in 2025

Open the free sample for your township

What one flagged appeal is worth to your firm

A flagged home cut the assessed value by $6,419 per appeal on average in 2025. At your contingency that is about $340 to $545 in fees per appeal filed, against $102 to $163 for any other home. A township list costs $490. Two won appeals pay for it.

Fee figures assume a 7% composite tax rate, the 3.03 state multiplier and a contingency fee of 25% to 40% of first-year savings. They are estimates, not county figures.

What is on the list

Every home in the township that the Assessor values at least 10% above the median of its comparables, largest gap first. For each home: the PIN, the property address, class, neighborhood, square feet, year built, the assessed value, how many comparables it has, their median value per square foot, the implied value, the gap and an estimate of the annual tax saving. It comes as a spreadsheet the day you buy.

Owner names and mailing addresses are not on the list. The county publishes them by PIN in its own address table (Cook County Open Data, dataset 3723-97qp), where your office can read them for the homes you choose.

For any home on your list, the uniformity evidence is built on request as a PDF the owner or your office can file: the subject record, the selection rule, how many properties survive each filter, every comparable with its assessed value, the median and the arithmetic. There is no charge for evidence on homes you bought.

How a home gets on the list

A comparable must be in the same assessor neighborhood and the same property class, within 15% on building size and 15 years on age, with the same building type and construction quality. A home needs at least ten comparables. Its implied value is the median of all of them, never a chosen few, and gaps above 40% are left off because they usually mean a record error rather than an argument. The method and the 2025 test in full.

Townships

Lists are sold to at most 5 firms per township per tax year, so the owners on your list are not in every firm's mailing. A township can be bought once its new values are published and until its Board of Review window closes.

Prices

Card payment at checkout, invoice by email. If a list turns out to be materially wrong against the county record, write within 7 days for a full refund. Terms of sale.

Questions firms ask

Can we check the numbers?

Every row carries the PIN, and every figure is the county's own: the Assessor's assessed values and characteristics from Cook County Open Data. Check any row against the Assessor's record before you rely on it. The free sample is there so you can do that before paying.

We already pull comps. Why buy this?

You can pull comparables for one PIN at a time. This ranks every home in the township against all of its comparables at once, so you know which owners to write to before the window opens.

How many firms get the same township?

At most 5 in a tax year. Once a township has 5 buyers, checkout for it closes.

Is this a referral or a lead service?

No. It is analysis of public records sold to law firms at a fixed price. We do not recommend any firm to any owner, we take no share of any fee, and we never contact owners. Your firm is responsible for its own solicitation under the Illinois Rules of Professional Conduct.

Is it legal advice or an appraisal?

Neither. It is a statistical comparison of assessed values published by the Assessor. Whether and how to file is your professional judgment.

Why is the data current?

The roll is read every day. A township goes on sale the day the Assessor publishes its new values, and the Board of Review calendar is read daily for filing windows.

Who is behind this?

AppealComps Assessment Desk, which builds and publishes the method on this site. Write to contact@appealcomps.com.