Residential Appeals

Appeals may only be filed during certain periods. Please read the general information about appeals for important information about rules for filing and deadlines for your area. You do not need to hire an attorney to file an appeal and filing is free at our office.

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. 


My home was recently reassessed. How did the Cook County Assessor's Office calculate the fair market value of my home?

Our staff used recent sales of homes similar to yours, in and around your neighborhood, to estimate your home’s value. Homes more similar to yours, or closer geographically to yours, make more of a difference in our calculation than other homes. Read the residential valuation page for more information.


How to file an appeal:

Appeals can be filed during a specific time period each year, depending on township. To find your appeal period for your township, please consult the Reassessment and Appeals Calendar.  

You will also need to select reason(s) for your appeal. Some common reasons are listed below.

For timely processing of appeals, filers are encouraged to file an appeal online.

Learn how to file an Online Appeal.


What are the common reasons for an appeal?

The Assessor's Office updates its determination of each property’s fair market value and corresponding assessed value once every three years. Residential property owners might determine the fair market value of their homes are accurate. But property owners also have a right to challenge the accuracy of those updated values by filing an appeal. If an appeal seeking a lower fair market value is granted, the property’s assessed value is lowered as well.

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 an error in the property's characteristics, such as incorrect square footage, you are encouraged to submit supporting documentation, such as dated photos with your appeal.

To support an appeal based on incorrect information, you are encouraged to supply documentation such as your property deed or an appraisal that is 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. Read the CCAO’s guide to using Cook Viewer to select comparable properties here.

You do not need to file a list of comparable properties with your appeal. Our analysts will check properties comparable to yours to determine if your assessed value is in line with the assessed values of those properties. 

You may, however, file your own suggested comparable properties with your appeal. You can 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. 

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 are not considered to be comparable properties to yours. 

What happens after my appeal?

Analysts review information submitted with the appeal and conduct additional research and analysis. For residential appeals, analysts determine whether the property’s estimated market value is fair and uniform compared to current data from the real estate market, comparable assessments of similar properties, and submitted data.

The analyst makes a decision to Change or Not change the estimated fair market value of your property.

The result of your appeal (change or no change) will be sent to you in the mail.



Frequently asked questions about appeals:

I’ve heard I should appeal even if I think my assessment is accurate. Is that true?

Analysts in our office make every effort to ensure all property valuations are as accurate as possible. Any errors in those valuations should be corrected through the appeals process. An appeal does not need to be filed if the original assessment is considered fair and accurate by the property owner. 

To ensure a fair system, all assessments and appeals – including yours, your neighbor’s, and the properties around you – must reflect the real estate market as fairly and accurately as possible. Doing so helps ensure no one pays more or less than his or her fair share of property taxes. 

Will an appeal reduce my property taxes? 

If an appeal is granted, your assessed value will be lowered. In most cases, a reduced assessed value will result in a tax decrease. (Tax bills are a reflection of assessments from the previous year, so 2020 assessments will be reflected in the second installment tax bills in 2021). 

But a decrease in your assessed value is not the only factor that determines your property taxes due to the interconnected nature of our property tax system.

Taxes are a function of levies passed by local governments to pay for schools, parks, libraries, police and fire departments, pensions, and other essential services. Property assessments determine how to distribute the levy fairly. If taxes are a pie, assessments are how we divide up that pie (though it’s a pie no one really wants to eat).

Even if your property’s assessed value increases, your taxes may not increase if additional tax levies are not passed by local governments or if your assessment does not increase as much as other residential or commercial properties in your area. In fact, an increase in new construction or an increase in the total assessed value of an area can reduce the overall tax rate for an area because there are more property owners to share the tax burden. 


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.


Appeal Online:

You may submit your appeal and supporting documents entirely online when the property's township is open for appeals.


PDF Forms:

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.