How to Appeal Your Property Taxes in Illinois

How to appeal your property taxes in Illinois

To appeal your property taxes in Illinois, you file a formal challenge to your home's assessed value with your local township or county assessor and, if needed, your county board of review — arguing that the assessment is too high or unequal compared with similar properties, and supporting your claim with evidence such as comparable sales, a recent appraisal, or proof of property errors. In Illinois, you appeal the assessed value of your property, not the tax bill or the tax rate directly, because your assessment is the number that drives what you owe.

The steps below explain the process in general terms. Because deadlines, forms, and evidence rules vary by county and township and can change year to year, always confirm the specifics on your own assessment notice and your county assessor's or board of review's official website before you act.

How property assessment works in Illinois

Illinois property taxes are based on your property's assessed value, which is generally intended to reflect a share of its fair market value. Local assessing officials (often at the township or county level) set that value, and your tax bill is calculated from it after exemptions, equalization, and local tax rates are applied.

You have grounds to appeal when you believe your assessment is:

• Too high — the assessed value implies a market value greater than what your home would realistically sell for.
• Unequal (non-uniform) — comparable homes in your area are assessed at lower values than yours, meaning you are paying more than your fair share.
• Factually wrong — the record lists incorrect details, such as the wrong square footage, lot size, number of bathrooms, or condition.

Where appeals are filed

Illinois uses a layered system. Most homeowners move through these levels in order, stopping as soon as they get a satisfactory result:

1. Assessor review (informal or formal). Many townships and counties let you first raise concerns directly with the assessor's office, sometimes informally.
2. County board of review. This is the primary formal appeal body at the local level. You submit an appeal, provide evidence, and may attend a hearing.
3. Illinois Property Tax Appeal Board (PTAB) or circuit court. If you disagree with the board of review's decision, Illinois generally provides a further path — typically PTAB or, in some situations, the courts.

Confirm which bodies apply in your county and how each one wants appeals submitted, since larger counties (for example, Cook County) may have their own procedures and portals that differ from other counties.

Watch your deadline

Appeal windows in Illinois are time-limited and are typically tied to when assessments are published or when your assessment notice is dated. As a general rule, the window to file often opens after assessments are made public and closes a set number of days later.

Do not rely on a remembered date. Check the deadline printed on your own assessment notice and on your county's official site, because missing the window usually means waiting until the next assessment cycle.

Step-by-step: appealing your Illinois property taxes

1. Read your assessment notice carefully. Note the assessed value, the property details on record, the appeal deadline, and instructions for where and how to file.
2. Verify the property record. Look up your property card or record online and check for factual errors in square footage, lot size, room counts, or condition.
3. Estimate your fair market value. Work out what your home would realistically sell for, since the assessment is meant to reflect market value.
4. Gather comparable evidence. Collect recent sales of similar nearby homes, and/or assessments of comparable properties to show your home is over-assessed or assessed unequally. A recent independent appraisal or documentation of damage or defects can also help.
5. Complete the required appeal form. Use the form your county board of review or assessor specifies, and follow its exact submission method and format.
6. File before the deadline. Submit your appeal and evidence through the required channel (online portal, mail, or in person) and keep proof of filing.
7. Attend the hearing if offered. Some appeals include a hearing where you present your case; be concise and lead with your strongest comparables or errors.
8. Review the decision and consider next steps. If the board of review's result is unsatisfactory, look into the further appeal options available in Illinois, such as PTAB or the courts, and note their separate deadlines.

Evidence checklist

• [ ] Your assessment notice and property record card
• [ ] Recent sale prices of comparable nearby homes
• [ ] Assessed values of comparable properties (for a uniformity argument)
• [ ] A recent independent appraisal, if available
• [ ] Photos or documentation of defects, damage, or needed repairs
• [ ] Any correction of factual errors in the county's record
• [ ] The correct county appeal form, completed
• [ ] Proof of timely filing

Tips for a stronger appeal

• Argue value or uniformity, not your tax bill. The board decides assessment value; complaints about the rate or the amount owed belong elsewhere.
• Choose truly comparable properties. The closer in location, size, age, and style, the more persuasive.
• Be organized and factual. A clear, evidence-first presentation tends to land better than a general objection that taxes feel too high.
• Check your exemptions separately. Homestead and other exemptions can reduce your bill and are handled apart from a value appeal — make sure you are receiving the ones you qualify for.
• Keep copies of everything. Retain your filing confirmation, evidence, and any correspondence.

Appealing takes some effort, but for many Illinois homeowners it is a straightforward, low-cost way to make sure they are not over-assessed. Start with your assessment notice, confirm your county's deadline and rules, and build your case around solid comparable evidence.