Illinois Residential Lease Agreement
Illinois regulates how a security deposit is returned, what a lease has to disclose, and what must be attached to it. Since January 1, 2026, every written residential lease needs the state's Summary of Rights for Safer Homes as its first page. Chicago and suburban Cook County add their own ordinances with caps on late fees and, in the county, on the deposit itself.
What Illinois law does to this document
Returning the security deposit
To withhold any part of a deposit for damage, a landlord must give the tenant an itemized statement within 30 days after the tenant vacates or the right of possession ends, whichever is later, with paid receipts or an estimate followed by receipts. If no statement is furnished, the full deposit is due within 45 days after the tenant vacates. A landlord who refuses to supply the statement, or supplies it in bad faith, and does not return the amount due on time owes twice the deposit due plus court costs and attorney's fees. Since January 1, 2024 the Act is no longer limited to buildings with 5 or more units.
765 ILCS 710/1Interest on deposits in larger properties
A landlord of a building or complex with 25 or more units must pay interest on a deposit held more than 6 months. The rate is the passbook savings rate of the largest commercial bank based in Illinois as of December 31 before the lease began, which the state announced as 0.005% for December 31, 2025. Interest that has reached $5 or more is paid within 30 days after the end of each 12-month rental period, in cash or as a rent credit.
765 ILCS 715/1 and 715/2The Safer Homes summary goes first
A landlord must attach the state's Summary of Rights for Safer Homes as the first page of any written residential lease, whether new or a renewal. Each tenant signs the acknowledgment at the bottom of each page of the summary. The requirement took effect January 1, 2026, and a landlord who fails to comply is liable for the greater of the tenant's actual damages up to $2,000 or $100, plus court costs and attorney's fees.
765 ILCS 752/20 and 752/30Flood and radon disclosures
Before the lease is signed, a landlord must disclose in writing whether the property is in a FEMA Special Flood Hazard Area and any flooding the landlord actually knows of. For a garden, basement or first-floor unit, the landlord must also disclose flooding in the last 10 years. The disclosure goes in the lease and both parties sign it. For leases entered into on or after January 1, 2024, the Radon Awareness Act separately requires the landlord to provide the state's Radon Guide for Tenants, any records showing a radon hazard in the unit, and the statutory disclosure form.
765 ILCS 705/25; 420 ILCS 46/26Chicago: the RLTO
For rental units covered by Chicago's Residential Landlord and Tenant Ordinance, a lease may not set a late fee above $10.00 a month for the first $500.00 of monthly rent plus 5% a month of any rent above $500.00. A copy of the city's ordinance summary must be attached to each written rental agreement, including renewals. The city requires interest on deposits each year at a rate the Comptroller sets, which is 0.01% for 2026, an itemized damage statement within 30 days, and return of the deposit within 45 days.
Municipal Code of Chicago ch. 5-12, including 5-12-140(h) and 5-12-170Suburban Cook County: the RTLO
Cook County's Residential Tenant and Landlord Ordinance took effect June 1, 2021 and covers most rental units in suburban Cook County. It caps a security deposit at 1.5 times the monthly rent and requires its return within 30 days with an itemized list of deductions. The late fee is limited to $10 when rent is $1,000 or less, and to $10 plus 5% of the amount over $1,000 when rent is higher.
Cook County Residential Tenant and Landlord OrdinanceWhere people go wrong in Illinois
- Requiring rent by automatic bank debit only, when a landlord may not require a tenant to pay by electronic funds transfer under 765 ILCS 705/4.
- Using the generator's lease as produced, when it does not include the Safer Homes summary, the flood disclosure or the radon disclosure form, so the landlord has to add all three and put the summary first with each tenant's signed acknowledgment.
- Using a statewide form in Chicago or suburban Cook County with a late fee above the local cap or without the local ordinance summary, which the generator's draft does not attach.
How the generator works
A current residential lease, fixed-term or month-to-month, covering rent, deposit, maintenance, and the disclosures landlords now have to make. Answer a short interview and the draft assembles as you go, with Illinois already set as the governing state. Download it as PDF or Word. No fee. No account.