Assessor or Board of Review: which Cook County appeal comes first
The Assessor's appeal window comes first and the Board of Review's opens later. But you do not need the first to file the second: of the residential properties with a Board of Review decision for tax year 2025, 33.1% had no appeal to the Assessor that year.
The short version: file with the Assessor when your township's window opens, then file with the Board of Review when its window opens, whatever the Assessor decided. Owners the Assessor turned down still had their Board of Review appeal decreased 45.0% of the time for tax year 2025. After the Board, there is one more free level: the state Property Tax Appeal Board, within 30 days of the Board's written decision.
The three levels, in the order they open
- The Cook County Assessor. Its window opens township by township, once a year. In tax year 2026, across the 13 townships where we hold both windows, the Board of Review window opened between 27 and 69 days after the Assessor's closed.
- The Cook County Board of Review. A separate elected body with its own window per township. You can file whether or not you appealed to the Assessor, and whatever the Assessor decided. Its rules are strict on time: “No complaint will be accepted after a township's official filing period has closed” (Board of Review rules, Rule 7).
- The Illinois Property Tax Appeal Board (PTAB). After the Board of Review decides, “a petition for appeal to the PTAB must be filed within 30 days of the postmark date of written notice of the board of review's decision”, and “there is no charge for filing an appeal with the PTAB” (PTAB, read 17 Sep 2026).
Board of Review outcomes, by what happened at the Assessor
Residential (class 2) properties with a Board of Review decision, grouped by whether the same property appealed to the Assessor for the same tax year and how that ended.
| Tax year | Route | Board of Review appeals | Decreased |
|---|---|---|---|
| 2023 | No Assessor appeal that year | 149,090 | 31.2% |
| 2023 | Assessor appeal, value not changed | 151,277 | 36.2% |
| 2023 | Assessor appeal, value changed | 30,470 | 37.7% |
| 2023 | Assessor appeal not recorded as decided | 7 | fewer than 100 |
| 2024 | No Assessor appeal that year | 134,492 | 35.7% |
| 2024 | Assessor appeal, value not changed | 291,627 | 44.0% |
| 2024 | Assessor appeal, value changed | 63,505 | 29.8% |
| 2024 | Assessor appeal not recorded as decided | 607 | 34.1% |
| 2025 | No Assessor appeal that year | 148,347 | 37.2% |
| 2025 | Assessor appeal, value not changed | 260,522 | 45.0% |
| 2025 | Assessor appeal, value changed | 38,909 | 43.7% |
| 2025 | Assessor appeal not recorded as decided | 6 | fewer than 100 |
A property is counted once per tax year at the Board of Review. No share is printed from fewer than 100 appeals. For tax year 2025: 148,347 Board-only appeals (37.2% decreased), 260,522 after an Assessor appeal that changed nothing (45.0%), 38,909 after one that changed the value (43.7%).
What this can't tell you
- It is not causal. Owners who go to the Board of Review after being turned down may have stronger cases than those who stop, and the file cannot say.
- Deadlines are per township and per year. Check yours with the office before filing; our deadline check shows only windows we have compared with the offices' calendars.
- A decrease is not a lower bill by the same amount. Tax rates, the equalization factor and exemptions also move the bill.
- It is not legal advice, and CivicDelta does not file appeals.
The step-by-step filing guide is How to appeal your Cook County assessment yourself; the county-wide outcomes are in Who wins a Cook County appeal.
Every figure on this page, and where it came from
Every number above is recomputed from the loaded records each time this page is built. Last rebuilt 2026-09-28.
| Dataset | Dataset ID | Captured |
|---|---|---|
| Assessor - Appeals | y282-6ig3 | 2026-09-28 |
| Assessor - Assessed Values | uzyt-m557 | 2026-09-28 |
| Board of Review Appeal Decision History | 7pny-nedm | 2026-09-28 |
Cook County open data, loaded in full and reconciled against the publisher's own row count.
Questions people ask
Do I have to appeal to the Cook County Assessor before the Board of Review?
No. The Board of Review is a separate filing: of the residential properties with a Board of Review decision for tax year 2025, 33.1% had no Assessor appeal that year.
The Assessor denied my appeal. Is it worth going to the Board of Review?
The county's records say many owners win there: for tax year 2025, 45.0% of residential properties whose Assessor appeal changed nothing had their value decreased at the Board of Review. That describes other people's cases, not a prediction for yours.
What comes after the Board of Review?
The Illinois Property Tax Appeal Board. The petition must be filed within 30 days of the postmark date of the Board of Review's written decision, and there is no filing fee (PTAB).
Can I file late at the Board of Review?
No. Its Rule 7 says no complaint will be accepted after a township's official filing period has closed.