In 2024, the year the City of Chicago was reassessed, the Cook County Board of Review reduced 41.8 percent of its 324,618 residential decisions there. In 2023 the rate was 20.8 percent. The median cut in 2024 was 4.1 percent of assessed value, or $1,150. After the state multiplier, at Chicago's 2024 general tax rate, that is about $231 a year.
Chicago is reassessed again for tax year 2027, so city sellers will ask all year: "Should I appeal before we list?" In the latest cycle, the reassessment year was each region's best year for residential reductions. How Cook bills are paid, and how the contract splits them, decides who keeps the money.
Quick Answer
In the latest cycle, each Cook County region had its highest residential reduction rate at the Board in its reassessment year: 48.0% in the south and west suburbs (2023), 41.8% in Chicago (2024) and 55.6% in the north suburbs (2025). The median cut came to about $231 a year in tax in Chicago and $467 in the north suburbs. A seller can appeal while the township's window is open, and a lower assessment or a corrected record can make the listing's carrying cost look better. But Cook bills are paid a year behind, and at closing the seller usually pays the buyer for the seller's share of taxes not yet billed. So much of the dollar benefit often lands with the buyer. The clearest direct win for a seller is usually getting back their own missed exemptions.
The reassessment year, region by region
Residential PIN-level decisions at the Board of Review, latest three-year cycle:
- South and west suburbs, reassessed 2023: 48.0% of 110,214 decisions reduced; median cut 7.1% of assessed value. The next two years: 41.9% (2024) and 37.7% (2025).
- City of Chicago, reassessed 2024: 41.8% of 324,618 reduced; median cut 4.1%. The years around it: 20.8% (2023) and 26.4% (2025).
- North suburbs, reassessed 2025: 55.6% of 218,236 reduced; median cut 5.0%, or $1,926 of assessed value, about $467 a year at the north suburbs' 2025 average tax rate. The two years before: 34.6% (2023) and 31.2% (2024).
Two things follow for a listing conversation.
Timing. If the home's region is in its reassessment year, its township window has recently been the one where reductions were most common. The south and west suburbs are being reassessed now, for 2026. Chicago is next, for 2027, then the north suburbs. These are past rates among homes that appealed, not odds for any one home.
Size. A median cut worth $231 to $467 a year is real money to an owner who stays. To a seller who closes in a few months, much of it may never reach them. Run the money question below before you recommend anything.
How the money moves at a Cook County closing
Bills are paid a year behind. The taxes you pay this year are for last year. The Board of Review says its decisions usually show up on the next year's bill, as a lower bill, not as a refund check.
The seller pays for the time they owned the home. Those months haven't been billed yet at closing, so the seller usually gives the buyer a credit for them. The credit is commonly based on the last full-year bill, using whatever formula the purchase contract sets.
So who gets the savings? If the credit was figured from the old, higher bill and nobody settles up later, the seller has already paid their share at the higher amount. The lower bill that arrives after closing then saves money for whoever pays it, which is usually the buyer.
The purchase contract decides the details, including whether anyone settles up once the real bill comes out. Check what it says before you promise a seller anything.
Where the seller benefits directly
Missed exemptions from the seller's own years. If the home qualified for an exemption that never made it onto a bill, the Assessor has a refund process for it (the Assessor calls it a Certificate of Error). It covers tax years 2021 through 2025, and once approved, the Treasurer mails a refund check. This is money the seller overpaid on their own bills, so it is the clearest win a seller can get.
A long listing period. If the home may take a while to sell, a reduction can cut bills the seller will still pay.
Record errors. Correcting a wrong fact about the home, such as square footage or a basement the county thinks is finished, helps whoever owns it next and removes a question from the buyer's diligence.
Where the listing benefits
Buyers look at taxes. A home whose assessment was recently reviewed, or whose record was corrected, is easier to explain. Be careful how you say it:
- Say: "The assessment is currently under appeal," or "The county record was corrected this year."
- Do not say: "Taxes will be $X next year." Nobody can promise that.
What a pre-list review should cover
Before the listing goes live, check:
- The property record card. Square footage, bedrooms, bathrooms, basement, garage and class. See property record card errors.
- The seller's exemption history. Any missing years are the seller's own money.
- Improvement permits. Work that is permitted but not yet reflected in the assessment may raise the value later. The buyer's side may find it, so do not let it surprise anyone. See the permit your listing forgot.
- Whether a window is open, and whether it is a reassessment year. If the township's Assessor or Board window is open and the case is real, filing costs little. Decisions can take months, so do not tie the listing timeline to the outcome.
When to recommend an appeal
- The window is open now
- The evidence is real: a record error, comparable homes assessed lower, or a value the market does not support
- The seller understands the benefit may mostly go to the buyer, or the contract addresses it
When those are true, an appeal is reasonable, inexpensive and good for the listing's story. In a reassessment year, the record gives it more support. It never gives a guarantee.
Where Censum House fits
Censum House's Listing Advantage produces a branded pre-list tax report covering what the seller can fix first. Buyer Advantage then shows prospective buyers their own estimated bill after the seller's exemptions drop, under your brand. Figures are record-backed estimates, not tax advice.
The numbers behind this article
Rates and medians are Censum's tabulation of the Cook County Board of Review Appeal Decision History dataset (county open data, 7pny-nedm), last updated by the county on June 9, 2026. They are PIN-level residential decisions, including condominium units, among homes whose owners appealed. Medians are taken over reductions only. Tax equivalents multiply the median assessed-value cut by the state equalization factor and the Cook County Clerk's published rate for that year: 3.0355 and Chicago's 6.618606% general rate for 2024, and 3.0300 and the north suburbs' 7.996% average rate for 2025. Actual bills depend on each home's tax code. Censum is independent and not affiliated with Cook County or any government agency.
FAQ
Is a reassessment year a better year to appeal?
In the latest cycle, each region's residential reduction rate at the Board was highest in its reassessment year. That is history among homes that appealed, not a prediction for any one home.
Will an appeal delay the closing?
No. The appeal runs on the county's timeline, separate from the transaction.
Who gets the savings if a reduction comes after closing?
A Board cut usually shows up as a lower bill the next year, not a check. Whoever pays that bill, usually the buyer, gets the savings, unless the purchase contract settles up differently.
Should a pending appeal go in the listing?
Factually, if at all: "assessment under appeal." Never promise a result or a future tax amount.
Can the seller recover exemptions after selling?
Yes, for years the home qualified and the exemption was missing from a paid bill. The Assessor's refund process covers tax years 2021 through 2025, and the Treasurer mails the check.
Sources
- Cook County Assessor, Certificates of Error
- Cook County Assessor, Assessment Calendar and Deadlines
- Cook County Board of Review, Residential Appeals
- Cook County Clerk, Tax Extension and Rates: 2025 Tax Rate Report, released September 23, 2026
- Censum tabulation of the Cook County Board of Review Appeal Decision History dataset (Cook County open data), accessed November 7, 2026; PIN-level decisions; dataset last updated June 9, 2026.
Next step
Before your next listing appointment, check the seller's township window, the region's reassessment year and the seller's exemption history, then run a pre-list tax report. See Listing Advantage in Censum House
Censum LLC is a data and analytics company, not a law firm and not a tax advisor. You file your own appeal. Censum is independent and is not affiliated with Cook County or any government agency.