Illinois Property Tax Assessments and How to File an Appeal

Property taxes are the type of thing that garner a communal grunt from anyone that has had to deal with them, especially here in Illinois where property taxes are the second-highest in the nation. While having to pay taxes never goes away, being informed about the process will help you ensure you are not overpaying. In this article, we’ll cover the facts about property assessment in Illinois, specifically in Cook County, and what to do if you need to appeal the assessment. 



In Illinois, property taxes are assessed every three or four years depending on where you live; in cook county, it’s every three years. Every time your property is reassessed, you will receive a notice in the mail labeled “Notice of Proposed Valuation” or “Reassessment Notice”, which you can also access online here.

Tax bills are mailed twice a year, and the first bill is due in March. The first bill will always be 55% of the amount assessed the year prior. The second bill is mailed out and due around the end of summer and will be for the remaining amount due for the year. The second bill may be less or more than the first depending on if you qualify for any new exemptions, if there have been changes to the local tax rates, or if your property was recently reassessed at a higher or lower amount. 


Assessment Process

First, the assessor will determine the “market value” of a property. Once the market value is determined, 10% of that figure is calculated to give us the “assessed valuation”. Once the assessed valuation is determined, that figure is then multiplied by 2.91 (this is the state equalizer multiplier) and this figure is called the “equalized assessed value”. From here, any applicable deductions are factored in (e.g., homeowner exemption of $10,000 or more for seniors) to give you the “adjusted equalized assessment value.” Finally, the tax rate applicable to your property (depends on your city, county, and other local factors) of that number is calculated to give you the final tax amount. See the visual example below that we pulled from the Cook County Assessor’s website.


Sample Tax Assessment Breakdown


Appeal Process

If you receive a Reassessment Notice and there are errors or you feel that the calculation for your property is incorrect, you can file an appeal. There is a time limit for appeals, (about 30 days from when the notice is mailed), so it is best to know when your property is scheduled for reassessment, as it only happens every three years. Follow this link for a full calendar of when Cook County’s assessments are mailed and the deadlines to appeal. The appeal


Follow this link for more information regarding appeals for residentials properties, and this link for information about filing a condominium appeal. All the forms and information for appealing property taxes for the different property types can be found at this link. While you do not need to have a lawyer or financial consultant to file an appeal, having an experienced professional help you with this process can be helpful and is allowed as long as an “Owner/Lessee Verification Form” is mailed along with the appeal. 


Final Thoughts

Property tax rates in Illinois are the second highest in the nation, and many think that it will rise to the number one spot after the recent increase in Chicago’s property taxes. Do not be surprised if your rates increase in the coming years, but instead be prepared and ready to file an appeal. It never hurts to try to reduce a bill!