In tax year 2025 the Cook County Board of Review issued 54,265 PIN-level decisions on commercial and industrial property. It reduced 14,993 of them: 27.6 percent. Attorneys filed 99.3 percent. When the Board did cut, the median reduction was 16.1 percent of the Assessor's value.
Of the 39,219 commercial decisions that came back unchanged, 6,078 (15.5 percent) carried a code for missing documentation or failure to follow Board rules. Those codes describe what was missing from the file, not a judgment on the property's income.
A complete income packet is a lot of work: three years of operating history, rent rolls, leases, vacancy affidavits, sometimes an appraisal. Censum's guide to building the income packet covers what the Board requires. This piece is about the step before that. Which properties deserve the packet at all?
Quick Answer
The Board reduced 27.6% of commercial and industrial decisions in tax year 2025 and 32.2% across 2023 through 2025, with a median cut of 17.5% of assessed value when it did. So the most valuable decision happens before engagement. Screen each property on three questions: is there an income discrepancy, an assessment or comparable discrepancy, or a change event? Then write down what evidence exists, what is missing, and when the honest answer is "not enough evidence yet."
The commercial record
Commercial and industrial PIN-level decisions at the Board of Review:
- 2021: 61,712 decisions, 43.8% reduced.
- 2022: 56,154 decisions, 29.0% reduced.
- 2023: 56,296 decisions, 30.8% reduced; median cut 19.2% of assessed value.
- 2024: 57,960 decisions, 37.8% reduced; median cut 17.7%.
- 2025: 54,265 decisions, 27.6% reduced; median cut 16.1%.
Across 2023 through 2025: 168,521 decisions, 54,204 reductions, 32.2 percent. The median reduction on those 54,204 was 17.5 percent, or $18,080 of assessed value.
Two kinds of no-change decision matter for screening. Across the same three years, 114,249 commercial decisions came back unchanged:
- 18,148 (15.9%) carried "no documentation submitted in addition to complaint form" or "failure to comply with Board of Review rules or requests and/or a failure to provide evidence supporting a decrease."
- 21,172 (18.5%) carried "consideration given to cost, income, or market data and/or your appraisal." The Board considered the data and made no change.
The first group is a documents problem. The screen catches it by asking, before engagement, whether the owner can produce the records. The second group is a divergence problem. The screen catches it by testing whether the property's numbers actually differ from the Assessor's assumptions before anyone builds the packet.
Question 1: Is there an income discrepancy?
What the Assessor assumes. For income property, the Assessor's model applies market assumptions for rent, vacancy, expenses and capitalization rate by property type and area.
What the property shows. Documented income and occupancy: rent rolls, Schedule E or entity equivalents, leases, vacancy history.
The test. Does the property's documented net income sit materially below what the Assessor's assumptions imply? If so, why: a lost anchor tenant, below-market legacy leases, unusual expenses?
Red flags. The owner cannot produce three years of records. Leases are with related parties. Income drops only in the year under appeal, with no explanation.
Question 2: Is there an assessment or comparable discrepancy?
What to check. Property class, building area, land area, and the assessment per square foot against similar properties.
The test. Is the property assessed at a higher level than comparable properties, or does the record carry the wrong area or class? Missing or wrong building area is common in commercial records, and it changes everything downstream.
Red flags. No truly comparable properties nearby. Comparables from a different assessment year or class.
Question 3: Is there a change event?
What counts. A sale, a vacancy, a fire or casualty, demolition, a code order, a tenant bankruptcy.
The test. Did something happen that the assessment does not reflect yet?
Caution. A change is a reason to look, not a conclusion. A recent arm's-length sale at or above the assessment limits a market-value argument, and may push the case toward uniformity instead.
The one-page review
For each property, the screen produces a single page:
- What the Assessor assumes
- What dated public or client-authorized evidence supports
- Where the two diverge, and by how much
- What is missing
- The recommended next step: prepare the packet, request specific documents, or decline for this cycle
"Not enough evidence" is a deliverable
An honest "not enough evidence yet" saves the firm preparation time and saves the client a filing that risks landing in one of the two no-change groups above. It also tells the client exactly what would change the answer, such as a vacancy affidavit or a corrected building area.
Include stable properties when you train reviewers. A property where nothing diverges teaches what "no case" looks like.
Keep client data in its lane
An owner's operating statements are provided for the tax matter. Use them for that matter. Public screening facts can be reused broadly. Client documents stay in the authorized workspace.
Where Censum fits
Docket's research view gives a fast first read on any Cook PIN, and its portfolio scan scores a list of properties at once. Censum is building a structured commercial review on the three-question shape above.
Censum is not a law firm, does not file appeals and never takes a share of legal fees. The screen supports a practitioner's judgment; it does not replace it.
The numbers behind this article
Counts, 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 decisions in the dataset's "Commercial and Industrial" major class, which excludes the incentive classes. Medians are computed on Decrease rows as the Assessor's total value minus the Board's, in assessed value, not market value or tax. Censum is independent and not affiliated with the Board or any county office.
FAQ
What share of commercial appeals does the Board reduce?
27.6% of commercial and industrial PIN-level decisions in tax year 2025, 37.8% in 2024 and 30.8% in 2023. Across 2023 through 2025 the rate was 32.2%. Past rates do not predict a given property.
Does passing the screen predict a win?
No. It identifies properties where the evidence may support a case. The Board decides.
How many properties should a firm screen at once?
Start with ten to twenty, including a few stable properties as controls, and record how long each review takes.
Can a recent sale hurt a commercial appeal?
It can. An arm's-length sale at or above the assessment usually weakens a market-value argument.
What if the owner will not share income records?
Then an income-discrepancy case is hard to build, and the file risks the no-documentation code. A uniformity or record-error case may still be possible.
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.
Sources
- Censum: Commercial appeals win one time in three; build the income packet
- Cook County Board of Review Official Rules, last updated July 27, 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
Run your next ten commercial prospects through the three questions before anyone opens a rent roll, and start with a first read in Docket. See Censum Docket
Censum LLC is independent and not affiliated with Cook County or any government agency.