What Illinois Sellers Must Disclose

Illinois requires sellers to put it in writing. The form is the Residential Real Property Disclosure Report. The seller must complete every item of the statutory Residential Real Property Disclosure Report and deliver it before a contract is signed, disclosing material defects known to the seller.

What the disclosure covers — and what it is

Illinois sellers must hand you the statutory Residential Real Property Disclosure Report before you sign a contract, answering specific questions including whether the property is in a floodplain, has had flooding or recurring basement or crawl-space leakage, and whether flood hazard insurance is carried. It covers material defects known to the seller, so it does not replace an inspection or a flood-map check.

Flooding: the answer that matters most

Illinois law specifically requires flood disclosure: the seller has to tell you about flood risk or history. Read that answer carefully, then verify it against the official map — FEMA's National Flood Hazard Layer is the map your lender will use, and a seller's 'never flooded' is not the same as 'not in a flood zone.'

The Illinois traps inside the paperwork

Exemptions vanish after a sale until you re-apply. In Cook County, all exemptions are removed from a home one year after a sale is recorded, and the assessor does not grant the Homeowner Exemption automatically; if you do not file your own application, you pay without the exemption the seller enjoyed.

Cook County reassesses on a different clock. Cook County reassesses every three years by region (city, north suburbs, south and west suburbs) while the rest of Illinois reassesses every four years, so a large value jump can land in your first reassessment year after purchase rather than at closing.

What no disclosure will ever tell you

A disclosure is the seller's knowledge, on the seller's timeline. It says nothing about the street's crime trend, the registry, the tax bill you will pay after the sale, permits pulled (or never pulled) for the renovation in the photos, or the rezoning working its way through the planning office. In Illinois, property tax reassessment works like this: Buying does not reset your assessed value to the price you paid; values change on the county's quadrennial reassessment cycle (triennial in Cook County). Your first bills can still be higher than the seller's because exemptions are removed after a sale and only return once you apply for your own — which is why the seller's current bill is a poor guide to yours. Pull those records yourself; they are all public.

Your checks, in order

• Read the disclosure line by line, and get 'unknown' answers in writing anyway — an unknown is a flag, not a pass.
• Run the exact parcel on FEMA's flood map.
• Estimate your post-sale tax bill with the Illinois records guide — never budget from the seller's bill.
• Check the address against the official Illinois registry.
• Ask the county for open and expired permits on the address before you waive anything.

Frequently asked questions

Is a seller disclosure form required in Illinois?

Yes — the Residential Real Property Disclosure Report. The seller must complete every item of the statutory Residential Real Property Disclosure Report and deliver it before a contract is signed, disclosing material defects known to the seller.

Does a Illinois seller have to disclose flooding?

Yes — Illinois requires flood disclosure. Verify it on the FEMA map anyway; the disclosure is the seller's statement, the map is the lender's rulebook.

The seller answered 'unknown' to half the form. Now what?

'Unknown' is legal in most regimes and useful to nobody. Treat every unknown as a job: inspection, permit search, and the county record file. If the seller genuinely doesn't know, the records usually do.

Sources: ilga.gov · opendocs.cookcountyil.gov · legalclarity.org · appealdesk.com