Cook County Lease Agreement: Required Terms, Disclosures, Deposits

A Cook County lease agreement for a residential rental in suburban Cook County must comply with the county’s Residential Tenant and Landlord Ordinance (RTLO), which dictates required disclosures, caps certain fees, bans specific clauses, and sets rules for security deposits, entry, and non-renewal notice.¹ The ordinance covers apartments, single-family homes, mobile homes, and subsidized units in unincorporated Cook County and the suburbs. It does not cover rentals inside the City of Chicago, which has its own ordinance, and it exempts owner-occupied buildings with six or fewer units from most provisions — though even those landlords cannot lock a tenant out illegally, and they must tell the tenant before accepting any fees that the RTLO does not fully apply.²

Required Terms and Attachments

A compliant lease begins with the standard identifiers: full legal names of all adult occupants, the complete address of the unit, the monthly rent, and the date rent is due. Those items settle who is responsible for the property and remove any ambiguity about what is owed and when.

Beyond the basics, the RTLO requires two attachments to every lease and every renewal. The first is a written summary of the ordinance, a standardized document published by Cook County that explains tenant rights in plain language. The second is the landlord’s full name, address, and telephone number, so the tenant knows where to send legal notices or reach someone about problems. When the property changes hands, the new owner must update this contact information.²

If a landlord skips the RTLO summary or any other required disclosure, the tenant can send written notice of the omission. The landlord then has two business days to hand over the missing documents, and continued non-compliance can give the tenant grounds to terminate the lease.²

Mandatory Disclosures

Section 42-805 of the Cook County Code layers several disclosure obligations onto the lease. Some appear in the lease text itself; others come as separate documents handed over before signing.

Utility Costs

The lease must state whether the landlord or tenant is responsible for each utility. If the tenant pays a utility directly, the service must be individually metered to that unit, and the landlord should disclose the previous twelve months of utility costs where known. If the tenant pays utility costs to the landlord instead of the utility company, the prior year’s costs must likewise be disclosed.² Where the landlord didn’t own the building during that period or doesn’t have the figures, they can substitute costs from a comparable unit or state that the costs are unknown.

Code Violations and Threatened Utility Shutoffs

If any building code violations have been cited in the previous twelve months, the landlord must disclose them in writing. The same rule applies to threatened utility shutoffs. Any notice from a municipality or utility company warning that water, gas, or electric service may be cut off has to be shared before the tenant signs.²

Foreclosure Notices

A landlord who has received a foreclosure notice, or receives one during the tenancy, must inform the tenant. This protects renters from being blindsided by a change in ownership or a bank taking possession.²

Lead-Based Paint

For any property built before 1978, federal law requires the landlord to disclose known lead-based paint hazards, provide copies of any available testing reports, and give the tenant a copy of the EPA pamphlet “Protect Your Family From Lead in Your Home.” The lease itself must include a lead warning statement, and the tenant must have the chance to review the material before signing.³ The RTLO summary separately requires disclosure of any known lead hazards.²

Radon Hazards

Illinois law adds a radon disclosure for residential units on the second floor or below, including basement-level apartments. Landlords must provide the “Radon Guide for Tenants” pamphlet, a completed “Disclosure of Information on Radon Hazards to Tenants” form, and copies of any radon test results from the previous two years, either at the time of application or before the lease is signed.⁴

Tenants get 90 days from the start of the lease to run their own radon test. If the result comes back at or above 4.0 pCi/L, the landlord can retest, mitigate, or allow the tenant to break the lease. If the landlord declines to mitigate, the tenant can hire a professional and spread the cost across remaining rent payments. When the landlord failed to provide the required radon documents in the first place, the tenant keeps the right to terminate over a high result at any point during the lease.⁴

Move-In Fees

Where the landlord charges a move-in fee, the tenant must receive an itemized estimate of the costs behind it. The fee cannot include routine maintenance or general upkeep, which are the landlord’s responsibility regardless.

Prohibited Lease Provisions

Section 42-804(F) of the Cook County Code lists provisions that are automatically unenforceable, even if both sides signed off. If any of these appear in the lease, they don’t bind the tenant:

Confession of judgment clauses that let a court enter judgment against the tenant without notice or a trial.⁵
Language requiring either party to waive the right to a jury trial.
Clauses eliminating the tenant’s right to receive termination notices, court filings, or other procedural protections required by law.
Non-disparagement provisions restricting what the tenant can say publicly or privately about the landlord or property.
Language capping either party’s legal liability or shifting responsibility for harm caused by one party’s negligence onto the other.
Clauses making the tenant pay the landlord’s attorney’s fees in an eviction, unless a court rule or statute specifically allows it.
Requirements that the tenant give more notice before moving out than the landlord gives for non-renewal, unless separately disclosed in writing.

The ordinance also caps late fees. A landlord cannot charge more than $10 per month for the first $1,000 of monthly rent, plus 5% of any rent amount above $1,000.⁵ On a $1,500 rent, that works out to $10 plus 5% of the extra $500, or $35 total. A lease demanding more is unenforceable on that point.

Security Deposit Rules

Deposits are where the RTLO gets most specific, and where the penalties for shortcuts bite hardest.

Deposit Limits and Where It’s Held

A landlord cannot demand a security deposit greater than one and a half months’ rent. The tenant can choose to pay any amount above one month’s rent in up to six equal installments over six months rather than all at once. The deposit must go into a federally insured account at a bank or financial institution in Illinois, kept separate from the landlord’s own money. It remains the tenant’s property and cannot be seized by the landlord’s creditors, even in a foreclosure.⁵

The lease must name the financial institution holding the deposit. If the landlord later moves the deposit to a different institution, written notice must reach the tenant within 14 days of the transfer.⁵ At the time the tenant pays, the landlord must issue a receipt showing the amount, the date, a description of the unit, and the name of the person who received the money. Skipping the receipt entitles the tenant to immediate return of the entire deposit.

Interest

Under the Illinois Security Deposit Interest Act, buildings with 25 or more units must pay interest on security deposits held longer than six months. The rate equals what the largest Illinois commercial bank pays on passbook savings accounts as of December 31 of the prior year. For 2026, that rate is 0.005%. If the accrued interest reaches $5 or more in a year, the landlord must pay it within 30 days of the rental anniversary, as cash or a rent credit. Any remaining unpaid interest is due when the lease ends.⁶

Return and Deductions

After the tenant moves out, the landlord has 30 days to return the deposit. Deductions are allowed only for unpaid rent — not for rent the tenant legitimately withheld — and for damage beyond normal wear and tear. Faded paint, light scuffs, and general aging from ordinary use are not deductible. If the landlord withholds any portion for repairs, an itemized statement of damages with estimated or actual costs must be mailed to the tenant’s last known address within 30 days.²

Penalties

Overcharging on the deposit, failing to return it, or skipping the itemized statement exposes the landlord to damages equal to twice the deposit amount plus attorney’s fees. And, as noted, no receipt at the time of payment means the tenant can demand the entire deposit back on the spot.²

Notice Rules Built Into the Lease

Several notice requirements shape what the lease should say and what a landlord can enforce during the tenancy.

Entry. A landlord must give at least two days’ notice before entering the unit, by mail, phone, written note, or any method reasonably designed to reach the tenant. In an emergency the landlord can enter without prior notice but must explain the reason within two days afterward. Repeated improper entries or entry demands used to harass a tenant can cost the landlord one month’s rent or twice the tenant’s actual damages, whichever is greater, plus attorney’s fees.²

Non-renewal. A landlord who does not plan to renew must provide at least 60 days’ written notice before the lease termination date. If the landlord misses that deadline, the tenant does not have to leave on the original end date. The tenant may stay for up to 120 days after the landlord eventually delivers written notice, with all existing lease terms remaining in effect during that period.² And the lease cannot demand more notice from the tenant to move out than the landlord itself must give, unless that asymmetry is disclosed in a separate written notice.⁵

Essential services and habitability. The landlord must keep the unit in compliance with applicable building codes and in habitable condition, covering structural integrity, running water, heat, working plumbing, electricity, and pest control.⁵ For general habitability problems, the tenant sends written notice and the landlord has 14 days to fix the issue before the tenant can withhold rent, make minor repairs up to $500 or half a month’s rent and deduct the cost, terminate for severe violations, or sue.² Essential services run faster: 24 hours to act on a heat, water, or electricity outage, and after 72 hours the tenant may terminate outright. A lease clause purporting to waive these remedies falls under the ban on waiving statutory protections.

Retaliation. A tenant who complains to a government agency, contacts the police, speaks to the media, or organizes with other tenants cannot be punished with a rent increase, service cuts, an eviction threat, or a non-renewal in response. A lease cannot contract around this protection.²

Signing and Delivering the Lease

The lease is finalized when both the landlord and all adult tenants sign. Electronic signatures are valid under applicable law, so signing does not have to happen in person. Once fully executed, the landlord must deliver a complete signed copy to the tenant within 30 days.¹ The first month’s rent and any security deposit or move-in fees are typically collected at this stage.

Keep proof of delivery. An email confirmation, a signed acknowledgment, or a certified mail receipt settles later disputes about which version of the lease the tenant received. The delivered copy is the tenant’s official record, and every term, disclosure, and attachment should match what was agreed to before either side signed.

1
Cook County Government. Residential Tenant Landlord Ordinance
2
Cook County Government. Cook County Renters Rights and Landlord Protections
3
US EPA. Lead-Based Paint Disclosure Rule Section 1018 of Title X
4
Illinois General Assembly. Illinois Compiled Statutes 420 ILCS 46/26
5
Cook County. Cook County Code – Residential Tenant and Landlord Ordinance
6
Illinois General Assembly. Illinois Compiled Statutes 765 ILCS 715 – Security Deposit Interest Act