Before reading about how to file a residential appeal, please read the Appeals Overview page.
Appeals may only be filed during certain periods. Before filing an appeal, check the Appeals Calendar and Deadlines page to see if your township is open for appeals.
Residential properties are all single-family homes, townhomes, condominiums, cooperatives, multi-family residential buildings and mixed-use property (residential and commercial) with no more than six units. They are classified as Class 2 properties.
How do I file an appeal?
We encourage the filing of appeals online. Please read our complete guide to online appeals before filing. If you are unable to file an appeal online due to lack of access, you can find PDFs of appeal forms here.
When should I file an appeal?
The last date to file an appeal is printed on your notice. Typically, you have 30 days to file an appeal after receiving your reassessment notice. If you missed your appeal period in a previous year, you may appeal the following year when your township is open for appeals.
Once you have appealed your reassessment; you do not need to do it each year, unless the characteristics of your property have changed significantly due to new construction, demolition, vacancy, or other issues. If an appeal is granted and nothing about the property changes then that value will remain your assessed value until the next reassessment.
To see the appeals schedule, go to cookcountyassessor.com/calendar.
What are the common reasons for an appeal?
Most commonly, property owners challenge the accuracy of the fair market value the office assigned their property due to uniformity or overvaluation. You can also file an appeal based on incorrect information about your property.
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 overvaluation, you are encouraged to submit supporting documentation, such as recent closing statements, or purchase prices of homes similar to yours, along with your appeal.
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.
How do I find and submit comparable properties for uniformity?
A comparable property is a property located within your assessment neighborhood which has characteristics similar to those of your property. These characteristics may include property classification, building age, building square footage, land square footage, and exterior construction. A complete list of your property's characteristics, along with your assessment neighborhood, can be found in the property characteristics section of your assessment notice or in your property's listing on our website.
You can find comparable properties online using interactive mapping on Cook Viewer. You should also read the CCAO’s guide to using Cook Viewer to select comparable properties.
When choosing comparable properties, select homes within your neighborhood code that closely resemble your own home in both size and style. If you submit homes that are very different from yours, they will not be considered as comparables.
You can also find a list of properties in your neighborhood in your community newspaper a few days after you receive your reassessment notice. The name of the newspaper and date of publication are indicated on your notice.
You do not need to file a list of comparable properties with your appeal, however. Our analysts will review other comparable properties and make a determination as to whether your assessed value is accurate based on homes similar to yours.
What are the guidelines for appeals due to flood or a catastrophic event?
Residential property owners who experience severe damage to their homes as a result of a catastrophic event are eligible to receive a home improvement exemption of up to $75,000.
This exemption is available when a residential structure is rebuilt after a catastrophic event. The exemption applies to the difference between the increased value of the rebuilt structure and the value of the structure before the catastrophic event.
The residential structure must be rebuilt within two years after the catastrophic event. The exemption will continue for four years following completion or until the next reassessment, whichever is later.
Catastrophic events are defined as severe damage or loss of property resulting from any catastrophic cause including but not limited to fire, flood, earthquake, wind, storm, explosion or extended periods of severe inclement weather. In the case of flooding, the structure must be located within a jurisdiction which is participating in the National Flood Insurance Program.
To file for a Catastrophic Event Exemption, the property owner or authorized representative must complete a Residential Assessed Valuation Appeal form.
Along with the appeal form, it is necessary to submit the following materials:
- a written description of the damages and the dates when damages occurred,
- the estimated date of completion for repairs or rebuilding, and
- all pertinent records such as photographs, insurance reports, building permits and occupancy certificates.
You may submit your appeal and supporting documents entirely online when the property's township is open for appeals.
For timely processing of your appeal, it is strongly recommended that you file online.
Note that any data and documentation supporting the appeal must be submitted concurrently with the appeal.
- Attorney Representative Authorization
- Documents in support of Appeal and/or Certificate of Error Form A: Includes Named Identification of Representation
- Documents in support of Appeal and/or Certificate of Error Form B: Excludes Named Identification of Representation
- Residential Appeal Narrative
- Field Check Request Letter
How often is my property reassessed?
Cook County is reassessed triennially, which means one-third of the county is reassessed each year. This year, the south suburbs will be reassessed. Your property may also be reassessed if there are significant changes due to a permit application, property division, demolition, or other special application.
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