How to Appeal Your Property Taxes in Will County (and How to File It Yourself)

by Brian Wittman

My assessment jumped about 25 percent, and my first reaction was the same one most people have, which is to assume somebody official had already checked the number and it must be right.

Nobody had checked it. I appealed on comparable properties, and the valuation came down somewhere in the range of 18 to 20 percent. Since then I have helped a client do the same thing. He got word that he won, and neither of us knows yet what it saved him in dollars, because that does not show up until the second installment bill lands.

Both of those were Cook County, where appealing your property taxes runs on a different calendar with different township deadlines. So the first thing I did when I started looking at Will County was check whether the rules were the same. They are not identical, and the differences are the kind that cost you the whole year if you get them wrong.

What is the deadline to appeal your property taxes in Will County?

For the 2026 assessment year, the Will County Board of Review complaint window runs from August 12, 2026 through September 14, 2026. That is the hard stop. Miss it and you are not appealing this assessment, you are appealing next year's, and you pay the bill in between either way. The underlying rule is that you get 30 days from the date your township's assessments are published in the local paper, so confirm your own township's publication date rather than assuming everyone in the county is on the same clock.

Why did my assessment go up when I did not do anything to the house?

Because Will County does not wait for you to do something. The county values property on a rolling three year sales study, so your 2026 assessment is built from sales that happened in 2023, 2024, and 2025. Your neighbors sold, and the number moved.

Two things worth knowing before you decide the county is out to get you. Illinois law targets an assessed value of one third of market value, and Will County currently sits at 33.46 percent based on that three year window, which is close to where it is supposed to be. And the state issued Will County an equalization multiplier of 1.0000 for 2025 taxes payable in 2026, the same as the year before. A multiplier of 1.0000 means the state applied no county wide adjustment at all. If your number moved, it moved at the township level, which is also where you go to argue about it.

One more piece of the calendar, because it changes how you should read this year's number. Illinois counties outside Cook run a general reassessment every four years, and Will County's next general assessment year is 2027, which shows up on the bill you pay the year after, since Illinois pays taxes in arrears. Treat whatever your assessment says today as a snapshot rather than a promise, and if you are in one of the fast growing towns out here, budget a cushion above the current bill instead of assuming it holds.

This is the part that matters over a long hold. A property tax bill is not a one year problem, and Illinois property taxes are already the line that decides what a house actually costs here. If your assessment is wrong and you leave it alone, you carry that error into every year you own the place, and over a five to ten year stretch a few hundred dollars a year of someone else's math becomes real money that was never yours to pay. It also quietly moves your monthly payment, which is why an escrow payment goes up on a loan whose rate never changed.

Where do you find your Will County assessment and property record card?

Start at the Will County Supervisor of Assessments. Their property search runs on your PIN, and the first two digits tell you your township, so a parcel in Manhattan Township, where I live after moving to Manhattan, IL, starts with 12.

What you actually want is the property record card, because that is the county's official description of your house. Pull it and read it like somebody is describing your home to a stranger. Wrong square footage, a bathroom you do not have, a finished basement that is not finished, a garage counted at the wrong size. Those are not arguments about opinion. Those are factual errors, and they are the easiest correction there is.

If you find one, call your township assessor before you file anything. An assessor who still has the books open can often fix a characteristic error without a formal complaint at all.

Do you actually have a case?

Will County recognizes four grounds, and it helps to know which one you are on before you start gathering paper.

Recent sale. You bought recently and your assessment came in above 33.33 percent of what you actually paid. This is the cleanest argument in the system, because the best evidence of what a house is worth is what somebody just paid for it.

Comparable sales. Similar homes nearby sold for less than what the county says yours is worth.

Equity. Homes like yours in your immediate area are assessed lower than yours. This is the one I used. You are not arguing about the market, you are pointing at the county's own numbers being inconsistent with each other.

Worth knowing before you pick it, because a lot of guidance online gets this backwards: equity carries a higher burden of proof than overvaluation. The Board's rules require clear and convincing evidence for an equity complaint, while an overvaluation complaint runs on a preponderance of the evidence, which is the ordinary standard. Equity spares you from having to prove what your house is worth. It costs you a tougher bar once you are there. If the sales in your area support an overvaluation argument, that is the lower hurdle.

Recent construction. You built, and the assessment exceeds 33.33 percent of what the build actually cost.

Should you check your exemptions before you appeal?

Yes, and do it first, because an exemption you are owed is easier to fix than an assessment you want changed. Will County administers the General Homestead exemption, a Homestead Improvement exemption covering up to $75,000 in added value, and exemptions for seniors and for disabled persons. Illinois also runs a Senior Citizen Tax Deferral program that lets qualifying seniors defer up to $7,500 a year against their equity.

An exemption you never claimed and an assessment that is too high are two separate problems. Plenty of people have both.

How do you actually file the appeal in Will County?

File through the Board of Review complaint portal, or on paper postmarked by the deadline. A few things the county tells you that most people find out the hard way:

The Board of Review requires a minimum of three comparable properties, and it is three whether you are arguing overvaluation or equity. Pick homes in your own subdivision and township, as close to yours as you can get, matched on size, construction, quality, age, style and condition, using sales from the prior three years. The Board's own standard is worth memorizing: the best comparables are the ones that require the fewest adjustments.

File them with the complaint, not at the hearing. This is the rule that quietly loses appeals. Comparable properties offered in testimony that were not submitted with the original complaint will not be considered by the Board at all. You cannot walk in with a folder. If it is not filed, it does not exist.

And for an equity complaint, your comps have to be in Will County. The Board will not consider out-of-county comparables for equity under any circumstances. Overvaluation comps can sit farther out, but then you carry the burden of proving they were the most comparable ones available.

You do not need an appraisal. The county's own residential complaint instructions never ask for one. If someone told you the price of entry is a few hundred dollars for an appraisal, that is not what the guide says.

And the one that stings: the county states that failing to check the box, sign, and date your complaint gets it dismissed, with no exceptions. People lose on that. Not on the merits, not on bad comps, on a missing signature. Before you submit anything, go back to the first page and look at the box.

One more thing the rules allow that people assume they cannot use: short sales and post-foreclosure sales count as market transactions. What does not count is a sale that was never really on the market, which the Board spells out as sales between related parties, properties never advertised, court-ordered and condemnation sales, partial interests, purchase options, trades, sale-leasebacks and long-term contracts. Your neighbor selling to his daughter is not a comp.

What happens after you file?

You get a written notice of a hearing date. Before you ever get there, your assessor may offer a stipulation, which is an agreed settlement, and that resolves plenty of residential cases without anybody sitting in a room. If you would rather not appear at all, residential filers can waive the hearing by signing an affidavit and letting the paperwork speak.

A written decision follows, usually weeks later. If it does not go your way, you have 30 days to take it to the Illinois Property Tax Appeal Board, and after that the courts are the last stop. Most homeowners never get past the Board of Review, and that is fine, because that is where the winnable residential cases get won.

Do you need to hire somebody to do this?

Honestly, no. Not for a straightforward residential case. Everything above is a Saturday morning and a printer, and the county built the process assuming a homeowner would walk through it alone. Nobody in this chain gets paid to knock on your door and tell you the number is wrong, and that includes me. That is not a conspiracy, it is just how the job descriptions landed, and it is why the number stays wrong until somebody who lives there decides to look.

Two things I will offer, in the order I actually mean them.

Finding comparable sales is real work I do as a broker, and it is the piece most people find hardest. If you want a set of comps for your own appeal, ask me and I will pull them.

And if you would rather hand the whole thing to somebody who does appeals for a living, reach out and I will point you to someone. No fee to me, no strings, nothing I am getting out of it.

The Bottom Line

The Will County window closes in mid September, and the Board posts the exact date each year. Between now and then, three steps do almost all of the work: pull your property record card and check it for factual errors, confirm you are getting every exemption you qualify for, and if the number still looks wrong, gather at least three solid comparables and file them with the complaint.

I went into my own appeal assuming the assessment was probably right and I was probably wasting an afternoon. It was not right. It is worth the afternoon to find out whether yours is.

Frequently Asked Questions

What is the deadline to file a property tax appeal in Will County?

For 2026, the Board of Review complaint window is August 12 through September 14, 2026. The general rule is 30 days from the date your township publishes its assessments, so confirm your township's publication date. Deadlines shift year to year, so never assume last year's date carries over.

How do I file a tax appeal in Will County?

File online through the Will County Board of Review complaint portal, or submit the official complaint form on paper postmarked by the deadline. The Board only accepts its official forms, and it requires a minimum of three comparable properties, submitted with the complaint rather than brought to the hearing.

Can I appeal my Will County property taxes myself, without hiring anyone?

Yes. The county's residential instructions are written for homeowners filing on their own and do not require an attorney or an appraisal. A straightforward residential case is genuinely a do it yourself project.

What documentation do I need to contest a Will County assessment?

Your property record card, at least three comparable properties matched on size, construction, quality, age, style and condition from your subdivision and township, sales data from the prior three years, and photos if the condition of your home is part of the argument. All of it has to be filed with the complaint, because comparables offered later at the hearing will not be considered. If you recently bought, your closing documents and transfer declaration do a lot of the work on their own.

Why did my Will County assessment go up when my house did not change?

Will County uses a rolling three year sales study, so your assessment reflects what comparable homes sold for in the three prior years. Nothing has to happen to your house for the number to move.

What happens if I miss the Will County appeal deadline?

You wait until next year. There is no late filing at the Board of Review, and you pay the current bill in the meantime. This is why the publication date matters more than almost anything else in the process.

What if the Board of Review turns me down?

You have 30 days from the decision to appeal to the Illinois Property Tax Appeal Board. Beyond that, the circuit court is the final option. Most residential cases are decided at the Board of Review level.

Brian Wittman is a licensed real estate broker (Real Broker LLC), mortgage loan originator (NMLS #2646598, NEXA Mortgage, LLC, Equal Housing Lender), and life insurance producer (Levinson & Associates). This article is for educational purposes only and is not financial, lending, tax, or legal advice, an offer, or a commitment to lend; all loans are subject to credit approval. Information is accurate as of the publication date; for current details and full disclosures, visit https://bluejeanbroker.com/disclosures.