How are residential property taxes assessed in Illinois?
Nora Devine explains that Illinois property taxes are theoretically based on fair market value—the price a property would sell for on the open market. While construction costs may serve as a starting point, they do not always reflect actual value. For example, a Lincoln Park property that reportedly cost more than $65 million to assemble and build might ultimately sell for only $13–15 million. This illustrates the principle that cost does not equal value in Illinois. Illinois is a value-in-exchange state, which means the property tax liability should be based on what a buyer would pay for the asset, not what the asset is worth for the current owner/user. Assessors, under Illinois law, should use a mass appraisal system to evaluate entire neighborhoods or subdivisions based on sales, construction, condition, and uniformity, which often leaves room for appeal when individual assessments are inaccurate.
What role do local government assessments play in determining property taxes?
In Illinois, local schools are the primary driver of property tax bills. Outside of Chicago, most school funding relies almost entirely on local property taxes. Chicago receives more centralized state funding, but across the rest of the state, communities depend on property taxes to sustain education budgets. This overreliance results in Illinois having the second-highest property tax rates in the nation, behind only New Jersey. While other states diversify revenue through service taxes, tolls, or natural resource levies, Illinois burdens real estate disproportionately, creating financial pressure for families and businesses.
What is the Property Tax Extension Limitation Law (PTELL), and how does it affect tax bills?
The Property Tax Extension Limitation Law (PTELL), enacted decades ago, limits annual property tax increases to approximately 5% over the prior year’s levy. For example, if a district collected $100 in property taxes last year, it can collect no more than $105 this year. Exceptions exist for new property developments, such as new subdivisions that come online that year or for expiring TIF districts that increase the tax base for the first time. Importantly, PTELL does not apply in home rule communities like Oak Park, where taxing bodies can levy as they see fit without seeking voter approval through the referendum process. While PTELL restrains rapid tax growth, school districts subject to PTELL can still seek additional funding through referendums.
What exemptions are available for Illinois homeowners?
The most common relief is the Homeowner’s Exemption, available to property owners who live in their homes. This reduces the taxable assessed value and lowers the bill. Cook County offers a larger exemption than other counties, though expansion statewide is under consideration. Additional exemptions include:
- Senior Exemption for qualifying homeowners over 65.
- The Senior Freeze program for low-income seniors can significantly reduce or even eliminate property tax liability.
Expanding exemptions too broadly can backfire by removing too many properties from the tax rolls, forcing tax rates upward to cover the levy demands of the school districts.
What should homeowners do if they believe their property tax bill is too high?
Devine emphasizes that in Illinois, once the tax bill is received, it is almost always too late to appeal. Unlike other states, appeals must be filed at the time of assessment notices, not after bills are issued. Homeowners should act immediately upon receiving reassessment notices, not wait for tax bills.
How does the appeal process work when a reassessment notice arrives?
In Cook County, residential assessed values are typically 10% of fair market value, which can confuse taxpayers. Hiring an attorney to monitor assessments, ensuring deadlines are not missed, and properly presenting arguments is a useful strategy in lowering real estate taxes. Appeals may address either:
- Property characteristics (errors in square footage, number of bathrooms construction details);
- Valuation issues (market value); or
- Assessment uniformity (uniformity compared to neighboring properties).
If errors are found, homeowners should seek corrections directly with the assessor during the appeal window. For valuation disputes, attorneys can provide stronger representation at the Board of Review or higher appeal levels.
What options exist if an error is discovered after receiving the tax bill?
While most appeals cannot be filed once the bill arrives, some errors can still be corrected retroactively. For example:
- Missing exemptions can be fixed for up to three prior years in Cook County or one prior year outside of Cook County. An attorney is not needed or helpful in this process.
- Property characteristic errors may be addressed through a Certificate of Error. Approval of a “C of E” in Cook County or a “CE” outside of Cook County will depend entirely on the assessor’s discretion, and a denial cannot be appealed further. Given the lack of higher recourse in the C of E or CE process, legal guidance is highly recommended when significant stakes are involved.