What Does an Illinois Seller Disclosure Report Cover?
Illinois requires nearly every home seller to complete a Residential Real Property Disclosure Report and hand it to the buyer before a contract gets signed. The seller disclosure report asks 24 yes-or-no questions about things like foundation problems, roof leaks, well and septic issues, and past flooding, based only on what the seller actually knows. It does not require an inspection, and it does not disclose the home’s condition to the world, only to the buyer sitting across the table.
By Kealan O’Neil | September 21, 2026
If you’re getting ready to list a home in Yorkville, Oswego, or Montgomery, this form is one of the first pieces of paperwork your agent will hand you, usually before you’ve even picked a listing price. I walk almost every seller through it the same way: answer it honestly, answer it early, and don’t let anyone talk you into skipping a line because “it’s probably fine.”
Here’s what’s actually on it, when it has to go out, and what happens if you get it wrong.
What’s Actually on the Form
The current Illinois seller disclosure report (Illinois REALTORS Form 108) asks about 24 specific conditions. You’re only answering based on what you’re aware of, not what a home inspector might find. The categories break down into a few groups:
- Water and structure: basement or crawl space flooding, foundation defects, roof and chimney leaks, wall, window, door, or floor problems
- Systems: electrical, plumbing, HVAC, fireplace or wood stove, well water, septic or sewer
- Health and environmental: radon, asbestos, lead paint or lead pipes, underground fuel tanks, mine subsidence
- Pests and history: current or past termite damage, prior methamphetamine manufacturing on the property
- Legal and boundary: unresolved code violation notices, boundary or lot line disputes, flood insurance status, and whether you’ve lived in the home in the last 12 months
Two of these categories, radon and lead paint, get their own separate riders under other Illinois and federal rules. If you want the full detail on those, I’ve covered both separately: radon disclosure requirements and the federal lead-based paint disclosure for homes built before 1978. This report is the broader form that sits around all of it.
You’re not required to guess or investigate. The legal standard is actual knowledge. If you never noticed a slow leak under the kitchen sink because it was hidden behind a cabinet, you’re not on the hook for missing it. But if you know about it and leave the box blank, that’s a different problem, covered below.
Timing: Before You Sign, and What Happens If It’s Late
The rule is simple to state and easy to get wrong in practice: the disclosure report has to reach the buyer before the contract is signed, not at closing, not during attorney review, before. Delivery can happen by hand, email, mail, or courier, but you want a dated, written acknowledgment that the buyer received it. Your agent should be building this into the timeline from the day you list, not scrambling for it once you’re under contract.
If the report goes out late, meaning it’s delivered after the contract is already signed, and it reveals a material defect the buyer didn’t already know about, the buyer gets 3 business days from receiving it to walk away from the deal entirely, with earnest money returned and no strings attached. That’s a real deal-killer risk over paperwork timing, not property condition, which is exactly why I get this into a seller’s hands as early as possible.
There’s also a continuing obligation piece worth knowing: if something changes, or you learn something new, between when you sign the disclosure and closing, you’re required to update it. This isn’t a one-time form you fill out and forget.
If you’re already through attorney review and moving toward closing, a late or incomplete disclosure report is one of the few things that can still unwind an otherwise solid contract, right alongside an earnest money dispute if the deal falls apart.
If You Knew and Didn’t Say So
Selling a home “as-is” is common in the Fox Valley, especially for older homes in Yorkville and Montgomery that need work. But as-is only shifts who pays for repairs. It doesn’t get you out of filling out the seller disclosure report, and it doesn’t protect you if you knowingly leave something off it.
If a seller checks “no” on a question they actually knew the answer to, and that turns out to be false, the buyer has grounds to pursue damages after closing under the Illinois statute that governs this form. This is a real category of Illinois real estate litigation. Multiple Illinois law firms field these calls regularly: a buyer moves in, finds a foundation crack, water intrusion, or a septic failure the seller clearly knew about, and comes looking for a remedy.
There’s a limited window to bring that kind of claim, and it starts running once the buyer takes possession, so this isn’t a liability that lingers forever, but it’s also not something you want hanging over a sale you thought was closed. Every situation is different here, and this is exactly the kind of question worth a five-minute call with a real estate attorney before you sign, not after a buyer calls you six months later.
The practical fix is almost always the same: if you’re not sure whether something counts, disclose it anyway. Note what it was, what you did about it, and when. A disclosed, explained issue almost never kills a deal. An undisclosed one, discovered later, can cost far more than the repair would have.
The One Exception: New Construction
If you’re buying new construction instead of resale in Yorkville, Oswego, or Montgomery, this entire form doesn’t apply to you. Illinois exempts newly constructed property that’s never been occupied from the disclosure requirement, because there’s no prior owner with knowledge to disclose.
That’s a real, practical difference between the two paths, on top of the SSA and property tax questions that already separate new construction from resale in this market. It doesn’t make new construction better or worse. It just means the questions you’re asking shift: instead of “what does the seller know that I don’t,” it’s builder warranty coverage, punch-list items, and how the home performs once it’s actually lived in.
Your specific situation, whether you’re the one filling this form out or the one reading someone else’s, depends on the home, the timeline, and what’s actually known. That’s exactly the kind of thing worth walking through with someone who does this daily in this market before you sign anything.
Common Questions About the Disclosure Report in Fox Valley Sales
Sellers and buyers in Yorkville, Oswego, and Montgomery ask versions of these questions constantly once they see the form for the first time.
Do I have to disclose something I already fixed?
Does selling my house “as-is” mean I skip the disclosure report?
What happens if the disclosure report shows up after I’ve already signed?
Do new construction homes come with a disclosure report?
What happens if a seller knowingly leaves something off the form?
If you’re working through a disclosure question, a listing timeline, or the new-construction-versus-resale decision for your own home in Yorkville, Oswego, Montgomery, or anywhere in the Fox Valley, I’m happy to walk through it with you. Call or text Kealan at 630-425-8815.
This post is part of our Illinois purchase contract guide. The other two required disclosures are covered in our posts on radon disclosure in Illinois and lead paint disclosure.
About Kealan O’Neil
Kealan O’Neil is the Designated Managing Broker and founder of O’Neil Property Group, an independent real estate brokerage based in Yorkville, Illinois. He and his team help buyers and sellers in Yorkville, Oswego, Montgomery, and the surrounding Kendall and Kane County communities, and he owns and manages a local rental portfolio, so he approaches every decision as both a broker and an investor. Call or text Kealan at 630-425-8815.
This post is general information about real estate in the Fox Valley, not legal, tax, or financial advice. Real estate laws, tax rules, and municipal ordinances change, and how they apply depends on your specific situation. Talk with a licensed attorney, CPA, or lender before making decisions about a purchase, sale, or tax matter. O’Neil Property Group is a licensed Illinois real estate brokerage.