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Question & Answer

The Cook County Tax Assessment Process

What is a tax assessment?
What effect does my tax assessment have on my tax bill?
Who determines my tax assessment?
Why was my property reassessed?
Why does my tax assessment appear to be so low?
Can I appeal my tax assessment?
How do I appeal my tax assessment?
Do I need an attorney to appeal my tax assessment?
How often can I appeal my tax assessment?
When can I file a tax objection lawsuit in Circuit Court?
I own a condominium unit, should I appeal my taxes individually, or collectively with the other unit owners?

What is a tax assessment?
A tax assessment is a value associated with a parcel of real property that is used to calculate the taxes paid on that property.

What effect does my tax assessment have on my tax bill?
Your tax assessment is directly related to your final tax bill. Your annual tax liability is calculated by multiplying your final assessed value by your equalized local tax rate.

Who determines my new tax assessment?
The Assessor's Office is charged with the responsibility of estimating a market value for your property.  This is because your real estate tax bill is based upon your market value.  This is known ad valorem.  

Why was my property reassessed?
Every property in Cook County is reassessed on a triennial reassessment cycle. So every three years, regardless of when the property was purchased, or when your tax assessment was last appealed, your property will be reassessed. Generally, the assessed value given to your property during the reassessment year will remain in affect for a period of three years until the property is next reassessed. Likewise, if the assessed value of your property is successfully appealed, that lower value will remain in effect for a period of three years. The Assessor's Office has the ability to reassess any property at any time; however, reassessment is uncommon outside of the ordinary cycle.

Why does my tax assessment appear to be so low?
The assessed value of your property is a fraction of Assessor's estimated market value of your property. In Cook County beginning with the tax year 2009, all residential property will be assessed at 10% of market value and all commercial property will be assessed at 25% of market value. For a residential property, an assessed value of 20,000 would equate to an estimated market value of $200,000.  A commercial property with the same market value of $200,000, would have an assessed value of 50,000.

Can I appeal my tax assessment?
Yes. Every property owner has a legal right to contest their tax assessment prior to the issuance of a tax bill.

How do I appeal my tax assessment?
In Cook County, an appeal can initially be filed at the Cook County Assessor's Office. In the event that a taxpayer failed to file an appeal at the Assessor's Office, or is not satisfied with the results of an appeal, she may then file an appeal at the Cook County Board of Review. Further, a tax refund may be obtained by filing at the Property Tax Appeal Board (PTAB), or by filing a tax objection lawsuit in the Cook County Circuit Court.


Do I need an attorney to appeal my tax assessment?
Yes and no. Any person or entity may file an appeal directly to the Cook County Assessor's Office. However, a corporation, condominium association, or any other entity that is not a person, must retain an attorney to file an appeal at the Cook County Board of Review, the Property Tax Appeal Board, or to file a tax objection complaint in Circuit Court. Tax relief is often obtained subsequent to an appeal at the Assessor's Office.

How often can I appeal my tax assessment?
You can appeal your taxes every time your township is open for appeal. Each township in Cook County is open for appeal for a period of roughly one month each year at both the Assessor's Office and the Board of Review.

When can I file a tax objection lawsuit in Circuit Court?
A tax objection lawsuit can be filed 165 days subsequent to the due date of your second installment payment for each tax year. For example, since property taxes are paid one year in arrears, the due date of your second installment payment for your 2007 taxes would be roughly November of 2008. At that point you would have 165 days to file your objection in Circuit Court.

I own a condominium unit, should I appeal my taxes individually, or collectively with the other unit owners?
Though each condominium unit owner can appeal their unit individually, better results are generally obtained when an appeal is filed collectively on behalf of the entire condominium association.   Among other factors, this is because a major factor of your condominium assessment is the percentage of ownership declared in your condominium declaration.

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