Cook County Property Tax Appeal — Illinois

Typically, you have 30 days to file an appeal after receiving your reassessment notice. The last date to file an appeal for that year is printed on your notice. If you miss your appeal period in your reassessment year, you may appeal the following year when your township is open for appeals. Cook County's township-based filing periods mean timing is critical. Filing periods are announced by township and typically last 30 days. You should check the Cook County Assessor's website for your specific township's filing window.

You do not need to hire anyone to file an appeal for you. Filing an appeal is free and can be done online in as little as 20 minutes. The online system works for single-family homes, townhomes, multi-family residential buildings, and mixed-use properties with no more than six units. A new tool allows users to find and use comparable properties within this online application. If you experience issues with the online appeal system, please email Assessor.onlineappeals@https://cookcountyil.gov. You can access the online filing portal at https://cookcountyassessoril.gov/online-appeals.

The Homeowner Exemption reduces the Equalized Assessed Value (EAV) of a property by $10,000. EAV is the partial value of a property used to calculate tax bills. The most common is the Homeowner Exemption, which saves a Cook County property owner an average of approximately $950 dollars each year. It is important to note that the exemption amount is not the dollar amount by which a tax bill is lowered. Your property tax savings from the Homeowner Exemption is calculated by multiplying the Homeowner Exemption savings amount ($10,000) by your local tax rate. This means actual savings vary based on your specific tax rate.

The current protest window is for formal hearings with the BOR, which is usually where more complex issues are handled in Illinois. The long break between the two appeal types also allows you to put together more evidence, since BOR hearings do require more evidence and strong grounds for appeal. The Board does not determine property values. It only analyzes appeals presented by citizens who noticed inconsistencies in their property assessment. When analyzing these appeals, the Board can never increase the property's value, but only maintain or reduce it. Businesses and people of means have attorneys to represent them at BOR hearings, while using tax experts and other professionals to gather the right evidence.

Successful appeals in Cook County can take 6-12 months to complete through both tiers. Your reduction will be reflected on your next tax bill. A good rule of thumb is this: If the property characteristics on this notice are correct and the estimated market value is within 10 percent of what you think your home is worth then it is unlikely that an appeal would change your property's assessed value enough to significantly affect its property tax bill. The amount you can save depends on how overvalued your property is compared to similar properties in your area. Many homeowners who successfully appeal see reductions of 10-20% in their assessed value, which can translate to hundreds or thousands of dollars in annual tax savings.

To support an appeal based on uniformity, either you or our analysts can look at comparable properties (properties similar to yours) and determine whether the assessed value of your property is in line with the assessed values of other comparable properties. To support an appeal based on incorrect information in the property's characteristics, such as incorrect square footage, you are encouraged to submit supporting documentation with your appeal. Dated photos, a property deed, or other evidence used to support an appeal can be found in rules 13-24 in the Official Appeal Rules of the Assessor's Office. Any appraisals submitted with an appeal must be USPAP compliant. The key is showing that your property is either overvalued compared to market or assessed unfairly compared to similar properties.

If you miss your appeal period in your reassessment year, you may appeal the following year when your township is open for appeals. While most of Cook County has seen its appeal windows close, even those opened a third time thanks to emergency measures, a select few townships are still able to lower their assessments. If you already tried an assessor appeal and were rejected, you can try again at the BOR phase. If denied at both levels, you may file an appeal with the Illinois Property Tax Appeal Board (PTAB) within 30 days of the Board of Review decision. Additionally, you can file a Certificate of Error if you discover errors in previous tax years.

Changes in your tax bill due to changes in assessments or local levies will be reflected in your second installment tax bill the year following your reassessment. For instance, reassessments received in 2021 will affect the property tax bill issued in the summer of 2022. The next property tax bill that could be affected by successful appeals is the one scheduled to be sent in the Summer of 2026. This bill will reflect the 2026 property assessments for the first time, even though it is called the "second installment." Successful appeals in Cook County can take 6-12 months to complete through both tiers.