In the 2023 South and West reassessment, 29,830 PINs had an Assessor appeal with no agent on record and a result of no change. Half went on to the Board of Review. The Board reduced 63.2% of them.
The other 14,848 never filed at the Board. They read the Assessor's letter as the end of the road.
It is not. The Board is a separate venue with its own window, and that window opens only after the Assessor certifies the township. In a reassessment year that can leave months between the Assessor's letter and the Board's deadline.
Quick Answer
Owners who lose at the Assessor without help often stop. In 2023, 14,848 South and West PINs with no agent on the Assessor appeal got no change and never filed at the Board; those that went on were reduced 63.2% of the time. The Board opens each township only after the Assessor certifies it, so an owner who lost at the Assessor often has months before the Board deadline. For firms, these are warm, time-boxed matters that reward fast, clean intake.
Where the drop-off happens
Assessor appeals that ended in no change, by whether an agent was on record, and what happened at the Board in the same tax year:
| Tax year | No-change PINs | With an agent: went on to the Board | No agent: went on to the Board | No agent: reduced at the Board | No agent: never filed at the Board |
|---|---|---|---|---|---|
| 2023 | 191,132 | 97.8% | 55.4% | 59.3% | 20,585 |
| 2024 | 345,857 | 98.0% | 53.3% | 51.2% | 26,631 |
| 2025 | 302,370 | 98.3% | 61.6% | 59.2% | 21,354 |
When an agent filed the Assessor appeal, almost every no-change PIN went on to the Board. When no agent was on record, between 38% and 47% stopped. In 2025 those PINs were 21,354 of the 25,512 no-change PINs that never reached the Board.
Most of the no-agent PINs that did go on filed there without an attorney: 91.4% in 2023. The lane is mostly unrepresented owners.
"Reduced" here is a share of the PINs that went on, and those owners chose to go on. The rate is history, not the odds for the owners who stopped.
A no change is not a bad sign at the Board
Board reduction rates, all PINs, by what happened at the Assessor the same year:
| Tax year | After an Assessor no change | No Assessor appeal |
|---|---|---|
| 2023 | 38.0% | 27.4% |
| 2024 | 44.7% | 31.7% |
| 2025 | 45.2% | 30.6% |
The Assessor's decision does not bind the Board. In each of the last three years, PINs that arrived after an Assessor no change were reduced more often than PINs that skipped the Assessor. That is not proof that one causes the other. It is a reason not to treat the Assessor's letter as a verdict on the merits. See Board of Review vs. Assessor and your property has two appeal windows.
How the Board windows follow the Assessor
The Board opens townships in groups, each after the Assessor certifies it. Each group gets about a month to file, and evidence is due ten days after filing closes. The first four groups of 2026 covered 22 townships:
- Group 1: filing August 3 to September 1; evidence due September 11.
- Group 2: filing August 31 to September 29; evidence due October 9.
- Group 3: filing October 8 to November 6; evidence due November 16.
- Group 4: filing November 9 to December 8; evidence due December 18.
Townships that close late at the Assessor open late at the Board. The Assessor's 2026 calendar had Thornton, Rich and Bloom closing on November 23, December 4 and December 17, so their Board windows come after those dates.
In every township, the time between the Assessor's decision and the Board's filing deadline is the intake window. The Board posts each township's dates on its Dates and Deadlines page once they are set, and the Assessor's calendar shows when each township closes there.
Why the first file often lost
A self-filed Assessor appeal often has a fixable weakness:
- No evidence beyond the form. The Board's most common paperwork code for attorney filings is the same problem: 68,212 attorney-filed decisions from 2023 through 2025 cited no documentation beyond the complaint form.
- The wrong ground. "My taxes are too high" instead of overvaluation or lack of uniformity. See overvaluation vs. lack of uniformity.
- Weak comparables. Homes that are not similar, or sales that are not arm's-length. See why weak comps undercut a practice.
- A record error nobody checked. Square footage, class or characteristics the county has wrong.
A denial that never reached a real argument says little about the merits.
Intake when the clock is short
- Authorization first. Under Board Rule 2, the Board's own Attorney Authorization Form, unaltered, must be submitted before the complaint is finalized. Late authorizations are not accepted. Get it signed on day one.
- Tell the owner not to file too. Under Rule 10, the first complaint on a PIN controls and later complaints are void, a taxpayer complaint overrides an attorney filing, and a later pro se filing controls. An owner who filed alone at the Assessor may file alone at the Board.
- Verify the PIN set. Rule 9 requires all related PINs on one complaint. Condo parking and storage PINs are easy to miss.
- Check your own book. Run the PIN against your protected-client list. If another attorney is already of record, replacing counsel takes the Board's Substitution of Representation form.
- Get the Assessor decision. It shows what the first file argued and what it lacked.
- Build the file to the evidence date. Rule 14 sets evidence deadlines after each township closes. In 2026 each of the first four groups had ten days.
How you reach these owners
Outreach to people who are not your clients is governed by the Illinois rules on lawyer advertising and solicitation. Confirm current labeling and content requirements before any mailing.
Where Censum Docket fits
Docket's opportunity queue has a lane for exactly these matters: owners who filed on their own at the Assessor this cycle, got no change, and still have a Board window ahead. The queue ranks them with the rest of your territory by recoverable value and modeled confidence, with a boost for live Board windows, and Docket generates filing-ready evidence packets and forms from the queue.
Censum is not a legal referral service, never takes a share of legal fees, and does not file appeals or appear before the Board.
The numbers behind this article
Censum matched the Assessor's appeal records to the Board's decision records by PIN and tax year, using Cook County open data accessed November 7, 2026. Counts are PINs. "No change" means every Assessor appeal row for the PIN that year read no change. "No agent" means the Assessor row has no agent code or name. The Assessor's dataset carries a county warning that some years are being repopulated; 2023 through 2025 are populated. South and West means the 17 townships reassessed in 2023 and again in 2026.
Sources
- Censum tabulation of the Cook County Board of Review Appeal Decision History dataset (Cook County open data), accessed November 7, 2026; PIN-level decisions.
- Censum tabulation of the Cook County Assessor Appeals dataset (Cook County open data), accessed November 7, 2026; PIN-level Assessor appeal results.
- Cook County Board of Review Official Rules, Rules 1, 2, 9, 10 and 14, last updated July 27, 2026.
- Cook County Board of Review, Dates and Deadlines 2026 Session.
- Cook County Assessor, Assessment and Appeal Calendar, last updated November 6, 2026.
FAQ
Does an Assessor denial hurt the case at the Board?
It does not bind the Board, which reviews the complaint and evidence presented to it. In 2025, 45.2% of PINs that came to the Board after an Assessor no change were reduced, against 30.6% of PINs with no Assessor appeal.
Can the owner file at the Board without an attorney?
An individual owner can file on their own. Under Board Rule 1, a property owned by an LLC, corporation, condo association or other entity must be represented by an attorney.
What if the owner already filed at the Board?
Under Rule 10 the first complaint on a PIN controls and later ones are void, and a taxpayer's own complaint overrides an attorney filing. Sort it out with the owner before you file.
What if the Board window has already closed?
After a Board decision, further review goes to the Property Tax Appeal Board on its own short deadline. If the owner never filed at the Board, the next opportunity is usually the next assessment year.
Does Censum file or represent clients?
No. Censum LLC is independent property-tax intelligence and docket tooling. It is not a law firm. The attorney files and makes every legal judgment.
Next step
Pull the no-change PINs in your territory whose Board window has not opened yet, and have authorization forms ready before each window opens. See the Docket opportunity queue
Censum LLC is independent and not affiliated with Cook County or any government agency.