Chicago property tax: how the system works and how to appeal

Last updated 2026-07-09

How does Chicago property tax actually work?

Chicago sits entirely inside Cook County, so the Cook County Assessor's Office decides what your property is worth for tax purposes. That office reassesses every parcel on a three-year cycle grouped by township. The City of Chicago is carved into several townships, including Hyde Park, Jefferson, Lake, North Chicago, Rogers Park, South Chicago, and West Chicago, and each one gets its own reassessment year inside the cycle. ^[1]

Here is the money flow. The Assessor sets your assessed value (AV) at 10% of estimated market value for residential property and 25% for most commercial property. ^[2] The Cook County Clerk then applies the State Equalization Factor, the number everyone calls the "multiplier," which the Illinois Department of Revenue sets each year to pull Cook County assessments up to the statutory 33.33% level. The multiplier for tax year 2022 (billed in 2023) was 2.9706. ^[3] Multiply your AV by that number and you get your Equalized Assessed Value (EAV). Subtract any exemptions. What's left gets taxed at your composite rate, which is every overlapping taxing body added together: the City of Chicago, Chicago Public Schools, Chicago Park District, Metropolitan Water Reclamation District, Cook County, and more. ^[10]

Watch the math on a $300,000 home. $300,000 times 10% is a $30,000 AV. $30,000 times the 2.9706 multiplier is an $89,118 EAV. Subtract the $10,000 Homeowner Exemption and you have a $79,118 taxable EAV. Apply a composite rate somewhere near 6 to 8% and you land at roughly $4,700 to $6,300 a year. Your real rate depends on your exact address and the levies set that year. The Cook County Treasurer publishes prior-year rates by tax code. ^[4]

This two-step math is why Chicago bills confuse people. Your Assessor notice shows the AV, not the taxable number, so it looks small. The multiplier nearly triples it before any rate touches it. Understanding the multiplier is the single most useful thing you can do before you file an appeal.

What are the current Chicago property tax rates and bills?

There is no single Chicago rate. Your composite rate is every overlapping district's levy divided by the total EAV inside that district. In 2022, the most recent year with published final rates as of mid-2025, composite rates across Chicago ran roughly 6.5% to 8.5% of EAV depending on where you live, and Chicago Public Schools usually accounts for more than half of the total. ^[4]

To find your own rate, look up your tax code at the Cook County Treasurer's site, cookcountytreasurer.com. Your tax code prints on your bill and on the Assessor's property detail page. The Treasurer posts a full rate table for every tax code once bills are calculated.

The Treasurer mails two bills a year. The first installment is always 55% of the prior year's total tax, due around March 1. The second installment reflects the real current-year tax after exemptions and rate changes, and it usually falls due in early August, though the Cook County Board has stretched that date in some years. ^[4] Late payments run interest at 1.5% per month under 35 ILCS 200/21-15.

The table below shows approximate 2022 composite rates by property type, drawn from published Assessor and Clerk data. ^[10]

Property Type	Statutory Assessment Level	Typical 2022 Composite Rate Range (EAV)	Approx. Effective Rate on Market Value
Residential (1 to 6 units)	10% of market value	6.5% to 8.5%	0.65% to 0.85%
Commercial / Industrial	25% of market value	6.5% to 8.5%	1.6% to 2.1%
Vacant land (residential)	10% of market value	6.5% to 8.5%	0.65% to 0.85%

Effective rates on market value look lower than the EAV rate because the assessment level is only a slice of market value. Even so, Chicago's effective residential rates sit near the top of any major U.S. city. Lincoln Institute of Land Policy data keeps Chicago in the highest tier for residential property tax burden year after year. ^[6] Curious how that stacks up elsewhere? See our breakdowns of la county property tax and nyc property tax.

What exemptions can lower your Chicago property tax bill?

Exemptions cut your EAV before the tax rate hits, so every dollar of exemption is a dollar off your taxable base. Here are the main ones for Chicago homeowners. ^[2]

Homeowner Exemption. Any owner who lives in the home as a primary residence qualifies. It knocks $10,000 off EAV. No income limit. Apply once and it renews on its own until your ownership or occupancy changes. Cook County processed roughly 1.6 million Homeowner Exemptions for tax year 2022.

Senior Citizens Homestead Exemption. For owners 65 or older. Cuts EAV by another $8,000. You reapply each year by the posted deadline.

Senior Citizens Assessment Freeze. Household income limit is $65,000. It freezes your EAV at the base-year level so reassessment can't push it up. This is the most valuable exemption available if you qualify, because it locks your tax base in place. Annual application required. ^[2]

Persons with Disabilities Exemption. Cuts EAV by $2,000. Annual application, disability documentation required.

Veterans with Disabilities Exemptions. These scale from a $2,500 EAV reduction (30 to 49% disability) up to a full exemption at 100% service-connected disability. ^[2]

Long-time Occupant Exemption. For owners who have lived in the same property at least 10 years (or 5 years with income under $100,000) and whose EAV jumped past the threshold. Cuts EAV by up to $30,000 depending on income. Annual application required.

Every application goes through the Cook County Assessor's Office at cookcountyassessor.com. Most deadlines land in late winter or spring, before the second-installment bill is calculated, but check the site because dates move. A missed deadline isn't permanent. Some exemptions apply retroactively for up to three prior years. Filing for exemptions you missed is one of the fastest ways to get money back with no formal appeal at all.

How do you read your Cook County assessment notice?

The Assessor mails a reassessment notice whenever your township hits its reassessment year. The notice lists your property's class code, your prior AV, and your new proposed AV. It also carries the deadline to file a complaint with the Assessor. That deadline is specific to your township, it changes every year, and it usually runs 30 days from the mailing date. ^[1]

Your AV alone tells you almost nothing about the bill. Run this check instead. Take the new AV, multiply by the current multiplier (find it at tax.illinois.gov), subtract your exemptions, and multiply by last year's composite rate. The estimate will be off by whatever the levy changes, but it lands you in the right neighborhood.

The notice also shows the implied market value the Assessor is using, which is your AV divided by 0.10 for residential property. Compare that number to what similar homes have actually sold for in the last 12 to 18 months. If the Assessor's implied value is higher than what you could realistically get for your house, you have the facts for an appeal.

One thing that trips people up. Your reassessment year is when the value changes and when the Assessor appeal is open. In the off years, the AV holds steady unless there was new construction or a correction, so there's less to fight at the Assessor level. The Board of Review is open to you every year no matter what. ^[7]

How to appeal Chicago property tax: the full step-by-step process

Chicago appeals move through three forums in order. You don't have to use all three, but you have to clear the lower ones before you climb. Most homeowners settle at the Assessor or Board of Review level and never see a courtroom.

Step 1: Cook County Assessor's Office complaint. This is the first and fastest route. File online at cookcountyassessor.com during your township's open window. That window usually runs 30 days from the day the Assessor mails reassessment notices, and it opens once every three years. Outside the window, you can still request a Certificate of Error for a factual mistake such as a wrong property class, a clerical error, or a missed exemption. ^[1]

To file, create an account, find your PIN (Property Index Number, printed on your bill or shown in the Assessor's property search), and submit a formal complaint. You pick a basis: either the market value is wrong, or your property is assessed unequally next to similar homes (a uniformity complaint). Attach your evidence. The office reviews it and usually answers within a few months with a proposed reduction or a denial.

Step 2: Cook County Board of Review. If the Assessor says no or the cut is too small, file with the Board of Review at cookcountyboardofreview.com. The Board holds real hearings, which the Assessor does not. You can file with the Board every single year, not only in reassessment years. Each township's window shows up on the Board's calendar in the spring. ^[7]

The Board has three elected commissioners and a large analyst staff. Hearings are short, often 10 to 20 minutes, but they run under oath, and you can present evidence, call witnesses, and challenge the Assessor's numbers. For plain residential appeals, most people never appear at all. Plenty of cases get decided on the written evidence filed with the complaint.

Step 3: Illinois Property Tax Appeal Board (PTAB). PTAB is a state agency that hears appeals from the Board of Review. File within 30 days of the Board's final decision. PTAB hearings are more formal and can take 12 to 36 months to resolve, which makes them a real fit for larger commercial cases where the dollars justify the wait. For a typical Chicago house, I'll be honest: PTAB is usually not worth the time. ^[8]

Step 4: Circuit Court. You can also file in Cook County Circuit Court within 75 days of the Board of Review's decision (or within 35 days of a PTAB order). This route almost always needs an attorney and runs through a tax objection complaint under 35 ILCS 200/23-5. It fits high-value commercial property where the savings clear the legal bill.

What to file. Both the Assessor and the Board take two kinds of evidence: comparable sales (a market value argument) and comparable assessments (a uniformity argument). For market value, pull 3 to 6 arm's-length sales of similar homes from the last 12 to 24 months, ideally within a half-mile. For uniformity, pull the Assessor's data on 3 to 6 similar properties and show that their AV per square foot sits below yours. The Assessor's property search lets you look up any parcel's AV, square footage, and class code. ^[1]

A clean, organized packet beats a thick one. Staff read hundreds of complaints. Label each comparable, explain the adjustments you made for size or condition, and state your requested AV out loud. Don't say "it's too high." Say "I request a reduction to $28,500 based on the six attached comparable sales averaging $285,000 in market value."

For more on gathering and presenting evidence, see our guide to property tax taxation.

What are the appeal deadlines for Chicago property tax?

Deadlines are the biggest practical trap in this process. Miss one and you're locked out for the year at that level. The key dates move every year because they're tied to when the Assessor mails notices, and that timing shifts.

Forum	Typical Filing Window	How to Find Your Exact Deadline
Cook County Assessor (triennial)	~30 days from Assessor's mailing to your township	cookcountyassessor.com, township schedule page
Cook County Board of Review	Varies by township, roughly April through November	cookcountyboardofreview.com, calendar page
Illinois PTAB	30 days from Board of Review final decision	ptab.illinois.gov
Circuit Court (tax objection)	75 days from Board of Review decision	35 ILCS 200/23-5
First installment due	~March 1 each year	Cook County Treasurer
Second installment due	Typically early August (can be extended)	Cook County Treasurer

The Board of Review calendar for 2024 and 2025 lives at cookcountyboardofreview.com and lists each township's opening and closing date. Some townships close as early as May. Others run into November. Check it at the start of every year. ^[7]

PTAB posts its rules, forms, and recent decisions at ptab.illinois.gov, and that's the practical place to confirm any procedural detail before you file. ^[8]

How to appeal commercial property tax in Chicago

Commercial appeals climb the same four-step ladder (Assessor, Board of Review, PTAB, circuit court), but the evidence, the stakes, and the strategy all change.

Commercial property is assessed at 25% of market value, not 10%, so the tax base is 2.5 times larger relative to market value than a home's. ^[2] On a $2 million building, a 10% over-assessment costs roughly $5,000 a year in excess tax at a 6.5% rate. That math makes a formal appeal worth the appraisal and legal cost.

The strongest commercial evidence is almost always an independent MAI appraisal built on the income approach. The Board of Review's commercial division expects a full USPAP-compliant appraisal for income-producing property if you want a large reduction taken seriously. A good commercial appraisal in Chicago runs $2,000 to $7,000 depending on size and complexity, and that cost usually comes back in the first year if the reduction is real.

The Board also takes a capitalized income worksheet for smaller commercial properties. You report actual gross income, subtract vacancy and operating expenses, divide by a capitalization rate, and compare the result to the Assessor's implied market value. The Board posts cap rate tables by property type each year.

Uniformity comparables work for commercial too. If a similar office building two blocks over is assessed at $180 per square foot of EAV and yours sits at $220, that spread is your case. Pull the numbers from the Assessor's public data portal, which lets you download bulk parcel data. ^[1]

A timing note. Large commercial owners often file at both the Assessor and the Board every year, not only in reassessment years. The Board is open annually, and commercial values swing hard with lease changes, occupancy, and market shifts.

For how Chicago's commercial burden compares elsewhere, see our breakdowns for maricopa property tax and miami dade property taxes.

What evidence actually wins a Chicago property tax appeal?

Two kinds of evidence win at the Assessor and Board of Review: comparable sales (a market value argument) and comparable assessments (a uniformity argument). You don't have to choose. Filing both makes the case stronger.

Comparable sales. Pull sales of similar homes from the last 12 to 24 months within a sensible radius. For condos and townhomes, same-building or same-complex sales are best. For single-family homes, aim for within a half-mile and similar square footage, age, and bedroom count. Sources: the Assessor's own sales data (searchable at cookcountyassessor.com), the Cook County Recorder of Deeds, Zillow, or an appraiser's MLS pull. Your implied market value is your AV divided by 0.10. If your six comparables average $310,000 and the Assessor has you at $380,000, show that gap plainly.

Comparable assessments (uniformity). Pull 3 to 6 neighboring parcels of similar type and size from the Assessor's public data. Compare AV per square foot. Illinois law demands uniform assessment under the Illinois Constitution, Article IX, Section 4. ^[9] Section 4 reads that taxes "shall be levied uniformly by valuation ascertained as the General Assembly shall provide by law." If your neighbors sit at $25 per square foot and you're at $32, the law backs you regardless of what market value says.

Photos and condition documentation. If your property has deferred maintenance, structural trouble, or functional problems the Assessor's model never sees, document them with dated photos and, better yet, contractor estimates or an inspection report. The Assessor runs mass appraisal. It can't see the crack in your foundation or the furnace still running from 1987.

What doesn't work. Your purchase price alone, if the sale was more than two years back, carries little weight because conditions change. A CMA from a real estate agent is weaker than actual sales presented directly, though it beats nothing. Complaints about tax rates or how the city spends money mean nothing in a valuation appeal. Stick to the numbers.

For a structured way to gather comps and build the packet, the TaxFightBack DIY appeal kit walks through it step by step so you keep 100% of any savings instead of handing a contingency firm 25 to 40% of the first year's cut.

See also our broader guide on online tax payment for property for how bills flow after a win.

What happens after a successful appeal in Cook County?

When the Assessor or Board of Review grants a reduction, the revised AV goes to the Cook County Clerk, who recalculates your EAV, then to the Treasurer for billing. If the change happens at the Assessor level before bills go out, the corrected value shows up in that year's second-installment bill. ^[4]

If the reduction lands after the second installment was already calculated and billed, which happens often with Board of Review decisions that arrive in late summer or fall, you get a refund check from the Cook County Treasurer for the overpayment. Refunds usually take 60 to 120 days after the Board issues its final order.

A reduction this year does not carry forward on its own. The Assessor can reset your property in the next three-year cycle at whatever the model spits out. A Board of Review order applies only to the tax year you filed for. That's why people who win often re-file in the next reassessment year.

One exception matters. If you win a Senior Assessment Freeze, that freeze holds your EAV going forward as long as you keep qualifying and reapply each year. That's a durable benefit, not a one-year patch.

Other counties handle post-appeal refunds their own way. See how hennepin county property tax and ramsey county property tax run Minnesota's version of this.

Should you hire a tax attorney or appeal firm, or do it yourself?

Most contingency firms take 25% to 40% of the first year's tax savings. On a Chicago home where a win saves $1,200 a year, that fee is $300 to $480, pulled straight from your refund. For a straightforward residential appeal with clear comparable sales or uniformity evidence, that fee is hard to justify.

Professional help earns its keep on complex commercial appeals, multi-million-dollar portfolios, PTAB hearings, or circuit court objections. A good property tax attorney brings relationships, appraisal contacts, and procedural know-how that genuinely move the number in those rooms.

For residential DIY filers, the Assessor's online portal works without legal training. The Board of Review publishes a Self-Represented Filer guide on its site. ^[7] The evidence rules are real but not technically demanding for a prepared homeowner. What sinks DIY filers is missing a deadline, filing thin evidence, or forgetting to state an explicit requested value.

Nobody has clean data on DIY versus represented success rates specifically for Cook County. The closest figure comes from the Board of Review's annual report, which publishes overall reduction rates by property class. The Board reduced assessments in roughly 60% of residential cases filed with supporting evidence in recent reported years, though the rate shifts year to year. ^[7] That number says filing with good evidence works, no matter who prepares it.

Common mistakes that sink Chicago property tax appeals

Missing the township filing window is the most common mistake. The Assessor-level window is about 30 days and it does not extend. The Board of Review window is longer but it also hard-closes by date. Put both dates in your calendar the day your reassessment notice arrives.

Filing without a requested value is the second biggest one. You have to tell the Assessor or Board exactly what AV you're asking for, backed by evidence. "I think it's too high" gets denied.

Using stale comparables. Illinois tribunals want sales from the last 12 to 24 months. Sales from three years ago, or from a different market cycle, carry less weight and can drag down an otherwise solid case.

Appealing the tax rate instead of the assessment. Taxing districts set the rate, not the Assessor. The Assessor appeal only touches your AV. Evidence about how CPS spends money is irrelevant to the complaint and does nothing for you.

Forgetting to check exemptions first. Sometimes the faster win is a missed exemption, not a valuation fight. If you've lived in your home more than a year and never filed a Homeowner Exemption, that's $10,000 off your EAV, and it may be retroactive. Fix the exemptions before or alongside the appeal.

For how other states build their appeal systems, see our guides to broward county property taxes and hillsborough county property tax in Florida.

Frequently asked questions

How do I appeal my Chicago property tax assessment?

File a formal complaint with the Cook County Assessor's Office at cookcountyassessor.com during your township's open window, which runs roughly 30 days from when reassessment notices are mailed. If the Assessor denies your complaint or the reduction is too small, file with the Cook County Board of Review. Attach comparable sales or comparable assessment data and state an explicit requested assessed value.

What is the deadline to appeal property taxes in Chicago?

There are two key deadlines. The Assessor-level window opens when your township's reassessment notices are mailed and closes about 30 days later; it happens once every three years for your township. The Board of Review takes appeals every year with township-specific dates posted at cookcountyboardofreview.com. Missing either window locks you out for that year at that forum.

How much does it cost to appeal property taxes in Chicago?

Filing at both the Cook County Assessor's Office and the Board of Review is free. If you hire a contingency firm, expect to pay 25% to 40% of the first year's tax savings. A commercial MAI appraisal for a Board of Review commercial hearing typically costs $2,000 to $7,000. Circuit court tax objection appeals require an attorney and add legal fees.

How often can I appeal my Cook County property tax assessment?

You can file with the Cook County Board of Review every year, whether or not your township was reassessed. The Assessor-level complaint is open once every three years when your township is in its reassessment cycle, or any time there's a factual error that qualifies for a Certificate of Error correction.

What is the Cook County property tax multiplier and how does it affect my bill?

The Illinois Department of Revenue sets a State Equalization Factor, the multiplier, for Cook County each year to bring assessed values to the statutory 33.33% level. For tax year 2022 it was 2.9706. Multiply your assessed value by this factor to get your Equalized Assessed Value (EAV), the base your composite tax rate is applied to after exemptions.

How do I appeal a commercial property tax assessment in Chicago?

File with the Cook County Assessor during your township's reassessment window, then the Board of Review annually. For commercial property, the Board's commercial division expects a full USPAP-compliant appraisal using the income approach for income-producing properties seeking large reductions. Uniformity comparables from the Assessor's public data also work well. PTAB or circuit court fit large assessments where the savings justify the time.

What exemptions reduce Chicago property taxes the most?

The Senior Citizens Assessment Freeze is the most valuable if you qualify: it caps your EAV permanently as long as household income stays under $65,000. The Homeowner Exemption cuts EAV by $10,000 for any owner-occupant. The Long-time Occupant Exemption can cut EAV by up to $30,000 for qualifying long-term owners whose assessments jumped sharply.

When are Chicago property tax bills due?

Cook County issues two installment bills a year. The first installment, equal to 55% of the prior year's total tax, is typically due around March 1. The second installment, reflecting the actual current-year tax, is typically due in early August, though the Cook County Board has occasionally extended that date. Late payments run interest at 1.5% per month under 35 ILCS 200/21-15.

What is the difference between the Assessor appeal and the Board of Review appeal?

The Assessor-level complaint is an administrative review, usually handled on paper, open only during your township's reassessment window. The Board of Review holds formal hearings and takes filings every year for every township. The Board also holds the Assessor's work to a more formal evidentiary standard. Most practitioners file with both in reassessment years if the Assessor doesn't grant a satisfactory cut.

Can I appeal my property taxes if I just bought my home in Chicago?

Yes. A recent purchase price can be your strongest evidence if the sale was arm's-length, recent (within 12 to 24 months), and below the Assessor's implied market value. File the closing disclosure and HUD-1 with your complaint. If you paid above the Assessor's value, the office may use your price to raise your assessment, so check the math before filing.

What happens if the Cook County Board of Review denies my appeal?

You can appeal to the Illinois Property Tax Appeal Board (PTAB) within 30 days of the Board of Review's final decision, or file a tax objection complaint in Cook County Circuit Court within 75 days under 35 ILCS 200/23-5. PTAB hearings take 12 to 36 months and fit large commercial cases. Circuit court almost always requires an attorney.

How long does a Chicago property tax appeal take?

Assessor-level complaints usually resolve in 2 to 4 months. Board of Review decisions come out 3 to 9 months after filing, depending on township and case volume. PTAB can take 12 to 36 months. If you win at the Board of Review after the second installment was already billed, expect a refund check in roughly 60 to 120 days after the final order.

Do I need a lawyer to appeal my Chicago property taxes?

No, not for residential appeals at the Assessor and Board of Review levels. Both forums accept self-represented filers, and the Board of Review publishes a Self-Represented Filer guide. For PTAB hearings, complex commercial cases, or circuit court objections, a property tax attorney adds real value. The math tips toward professional help when potential annual savings top several thousand dollars.

How do I find comparable properties to support my Chicago appeal?

Use the Cook County Assessor's public property search at cookcountyassessor.com to look up assessed values, square footage, and class codes for neighboring parcels. The Assessor also makes bulk parcel data downloadable for uniformity analysis. For comparable sales, search the Assessor's sales data, the Cook County Recorder of Deeds, or real estate portals for arm's-length transactions within the past 12 to 24 months.

Sources

1. Cook County Assessor's Office, official website: Cook County Assessor assesses property on a triennial township cycle; complaint filing windows and parcel search data are publicly available
2. Cook County Assessor's Office, Exemptions page: Residential property assessed at 10% of market value; commercial at 25%; Homeowner Exemption reduces EAV by $10,000; Senior Freeze income limit $65,000
3. Illinois Department of Revenue, official website: State Equalization Factor (multiplier) for Cook County for tax year 2022 was 2.9706
4. Lincoln Institute of Land Policy, 50-State Property Tax Comparison Study: Chicago's effective residential property tax rates are among the highest of major U.S. cities in annual Lincoln Institute comparisons
5. Cook County Board of Review, official website: Board of Review accepts appeals every year for every township; filing calendar, Self-Represented Filer guide, and reduction rate data published annually
6. Illinois Property Tax Appeal Board (PTAB), official website: PTAB hears appeals from Board of Review decisions; appeal must be filed within 30 days of Board's final decision; hearings typically take 12 to 36 months
7. Illinois General Assembly, Illinois Constitution Article IX: Illinois Constitution requires uniformity of taxation; taxes shall be levied uniformly by valuation as provided by law
8. Cook County Clerk's Office, official website: Cook County Clerk applies the equalization factor and calculates composite tax rates by tax code after taxing district levies are certified