Overview of How Appeals Work

Should I appeal my assessment?

If the property characteristics listed on your assessment notice are incorrect, or if the estimated market value of your home is significantly more than what you believe your home could sell for in the current real estate market, you should file an appeal. The last date to file an appeal is printed on your notice. 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.

Will I pay less in property taxes if I file an appeal?

An appeal is intended to correct the accuracy of your property’s assessment. An increase (or decrease) in your home’s assessment does not lead to the same increase (or decrease) in your property taxes. The Assessor does not set property tax levies, rates, or bills.

Your property’s share of the total assessed value of all properties within your community affects your share of your community’s property taxes.

This means your home’s value can increase, while its share of property taxes could increase, decrease, or stay the same due to the reassessment of your city, village, or town. If other properties’ assessments increase more than yours, this can shrink your home’s share of property taxes.

Your property tax bill depends not just on your property’s assessment, but also its exemptions, the total assessed value of your community, and the levies passed by local taxing bodies. Your property tax bills list the taxing districts funded by your property taxes.

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.

I recently purchased my home. Why is the Assessor’s Office estimate of my home’s market value not the same as my purchase price?

A home’s recent purchase price is sometimes, but not always, a reflection of its true market value. Sale prices of a home depend on not just the characteristics of the home itself, but also the individual buyer, seller, and even the time of year. To be fair to all properties—those that have sold recently, and those that haven’t—the CCAO uses the same methods to estimate true market values.

Do I need to hire someone to file an appeal?

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.

You may have received a notice in the mail from a property tax firm saying they can file an appeal on your behalf. These notices do not come from our office and are sent by firms which charge you a fee based on their estimates of how much they think they can save you in property taxes. These estimates may or not be accurate.

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 more information about filing a paper appeal form here.

All filers must adhere to the Official Appeal Rules of the Cook County Assessor

When should I file an appeal?

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. Once you have appealed your reassessment once, 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.

To see the appeals schedule, go to cookcountyassessor.com/calendar.

How does the Assessor’s Office calculate the estimated market value of my property? The process used to calculate residential property and commercial/industrial property differs. See the following pages for more information:

How Residential Property Is Valued
How Commercial Property Is Valued

What is the difference between the estimated market value and the assessed value?

The estimated market value is what our office believes properties like yours are worth in the current real estate market. The assessed value of your home is the amount used to calculate your property taxes. For residential property, this is usually 10% of the estimated market value. For commercial property, this is typically 25% of estimated market value. Here is a list of property types with links to the forms you may need to upload into our online appeals system.

The kind of appeal you file depends on your property type.