The property tax situation in Cook County has spiraled out of control this year. Starting with a computer issue that delayed tax bills for months, the entire process appeared to break down. To make matters worse, when the bills finally arrived, it was revealed that homeowners across the Chicago area were seeing the largest tax increase in the county’s history, with a general spike of 16%. In some neighborhoods, increases jumped to over 100% for a few select neighborhoods, mostly those with working families and minorities.
This seems to have galvanized the people of Cook County into an uproar. With it becoming abundantly clear that many taxpayers simply can’t afford to pay these new taxes, let alone the first installment of taxes in 2026, the Cook County Board of Review (BOR) has taken the unprecedented step of reopening property tax appeals. While the dates for these new appeals are still in limbo, now is the time to start preparing for your appeal. While the timing may be unusual, the same rules used in regular sessions will apply to this second wave. O’Connor will go over the evidence that you need to prove your case to the BOR to get a reduction for your taxes in 2026.
Reductions can Help Your 2026 Bill
While the second installment in 2025 has been grabbing the headlines, there is no real option for reducing these bills. Instead, the BOR is focusing on 2025 values that will be used to calculate the first installment of 2026, due in April. Typically, the window to appeal these taxes would have already closed, but this special second session gives taxpayers another chance. If you protested already this year, then you cannot try again. This opportunity is for those who did not appeal, which is a good chunk of the population, especially in the hard-hit South and West sides.
Grounds for Appeal
While initial assessor appeals are quite simple, protesting to the BOR requires more evidence and significantly more time to prepare. When you appeal to the BOR, you must decide what grounds you intend to use in your appeal. Grounds include appealing on uniformity, where you assert that your property is overvalued compared to analogous properties near you. Market value is another route you can explore, as you can compare your property to similar ones that sold in your area. Correcting simple errors can be an easy way for you to save, and these issues are quite common in Cook County. Also, if you recently bought your home, you can use your closing documents to help prove the true value of your home. Deciding on your grounds for appeal is the first step, as it determines what evidence you need to gather.
Appealing on Uniformity
Although uniformity appeals are the most complex, they can also be the most rewarding. To prove that your property is overvalued compared to your neighbors, you must do a lot of legwork. First, you must document and photograph your property to establish a baseline. Ensure that you have your property’s assessed value and your permanent index number (PIN). Then, you must search your street or surrounding blocks for homes that are close to yours in size and condition. You then need to photograph these properties as well. Be sure to note each address so you can record it and use it to look up the PIN and information about the property.
The PIN can usually be found by looking up the address on the website of the Cook County Assessor’s Office (CCAO) or your local township. The BOR recommends that you have between three and five properties that are similar to yours in your evidence packet. You will need the photos of each property, their PINs, and their assessed value. With all of this in hand, you will hopefully be prepared for your hearing with the BOR. Due to the many steps and complexity, cases based on uniformity are often when taxpayers choose to join up with an attorney or tax specialist.
Market Value
If you believe your home or business is assessed above its value on the open market, then you can try to get it reduced. To do so, you must compare your property to the sale prices of similar ones. All of these sales must have occurred in the last three years. Gathering evidence for market value is generally the same as trying for uniformity, though with some added requirements. You must find and document properties in the same way, but must also have records of what they sold for. This can be found by contacting realtors in your area or searching your local assessor’s website.
Appeals using these grounds can be effective, as comparing sales in the past three years is how assessors in Illinois figure both their assessments and their equalization factor. In essence, you are using the assessor’s own evidence against them. With Cook County values being notoriously unreliable, if executed well, these appeals can easily show a disparity in the system. The downside, of course, is the time and effort needed to gather the evidence, which can be quite difficult for a layperson. This barrier of entry is why many middle-class or working people never explore appeals, compared to wealthier property owners that can hire firms to do it for them. The appeals process is often compared to having a second job for a reason.
Correcting Simple Errors
The 2023 reassessment of Cook County laid bare some of the basic problems in the CCAO’s process. Vacant lots were recorded as being homes, large businesses were shown to be much smaller, and homes with the exact same specifications were listed as being worlds apart. These simple errors could be easily avoided if the property owners appealed. These errors can be spotted by simply reviewing your assessment. Typically, any blatant errors can be easily remedied with informal assessor appeals. However, the window for those protests is closed, so it must be taken up with the BOR. These errors can be proven by a quick independent survey or presenting the blueprints for your property. It often helps to have a tax expert review your assessment every year just to spot these simple errors.
Presenting Your Case
Once you have your grounds for appeal and the evidence to back it up, you must then present it to the BOR. You can certainly do this yourself, especially when it comes to correcting simple errors or simply providing closing documents on a recent purchase. For more complex cases, you may want professional representation. This can only be done by attorneys, as Illinois law does not allow anyone else to represent you. You can give your portfolio of evidence to your attorney, who will then use it to secure a reduction with the BOR. In recent years, the BOR has shown a strong sympathy for homeowners when it comes to appeals, so much so that the CCAO has placed many of the current woes at their feet.
A Unique Time Crunch
Typically, the appeal season in Cook County is long and organized. Each township has a window for informal appeals, before the BOR opens up for 30 days to hear cases. This new reopening is uncharted territory, and townships could open at a moment’s notice. This means that if you are considering a protest, you need to gather data and evidence as soon as possible. Cramming a year’s worth of work into 30 days at the end of the year will be tough, but the rewards are certainly worth it.
O’Connor can Gather Evidence and Help Coordinate Your Case
If all of this sounds overwhelming, don’t feel alone, as that is almost certainly part of the system. We at O’Connor are here to help. As this article demonstrates, evidence is the most important part of your case. We will partner with you and do the heavy lifting, allowing you to have peace of mind. We will find comparable properties in your neighborhood to use in your case, documenting them carefully. In the case of market value, we will use our proprietary database, which contains thousands of sales records in your area, saving you a great deal of time and hassle. We will also review your assessment, spotting any simple errors that need to be addressed.
While we are not attorneys and cannot represent you in the appeal process, we can coordinate with an attorney to give them the best evidence possible. We will work with your attorney or engage one who knows exactly how to approach the BOR. Working with you and your legal team, we can provide you with the edge you need to win your case. Best of all, this evidence gathering and analysis will cost you nothing, and you will only pay a contingency fee if you are able to lower your taxes. We will even review your assessment for you every year, free of charge. If problems pop up, we will coordinate another appeal with you and your attorney. With things seemingly unraveling in Cook County, you will want your assessment and taxes analyzed annually, as it can help prevent similar disasters in the future.
