Cook County Residential Tenant Landlord Ordinance: The Suburban Landlord's Compliance Guide
Cook County Residential Tenant Landlord Ordinance: The Suburban Landlord's Compliance Guide
The most common mistake suburban Cook County investors make is assuming they've escaped Chicago's regulatory burden. They buy a rental property in Oak Park, Skokie, or Calumet City — safely outside city limits, they think — and operate it like a downstate landlord. No security deposit disclosures. A flat $100 late fee on a standard lease. No RLTO summary attached.
Then they receive a complaint in housing court and discover they've been in violation of the Cook County Residential Tenant Landlord Ordinance (RTLO) since the day they signed the first lease.
What the RTLO Is and When It Took Effect
The Cook County Board of Commissioners passed the RTLO in 2021, effective October 2021 for new leases. It extended a comprehensive set of tenant protections — modeled closely on the Chicago RLTO — to rental properties throughout suburban Cook County. If you own a rental property in Cook County that is not within the Chicago city limits, and no other specific municipal ordinance covers it, the RTLO applies to you.
Several suburbs maintain their own ordinances with specific provisions, including Evanston and Mount Prospect. Properties in those municipalities are generally governed by local ordinance rather than the county RTLO. For everyone else in Cook County's suburbs: assume the RTLO applies until you've verified otherwise with a local landlord-tenant attorney.
Who Is Exempt from the RTLO
The RTLO includes a "mom and pop" exemption that is narrower than it sounds. A landlord is exempt if:
- The owner occupies one of the units in a building of six units or fewer, and
- The building has six or fewer rental units total
Single-family home landlords who own only that one property may also qualify for certain exemptions. The key word is "only" — if you own the single-family home plus any other rental property, you may not qualify.
Anti-lockout provisions apply universally, even to otherwise exempt units. Even if your building qualifies for the owner-occupied exemption in all other respects, you cannot change the locks, remove doors, or shut off utilities to force a tenant out. Self-help evictions carry severe penalties regardless of exemption status.
Security Deposit Rules Under the RTLO
Unlike Chicago's RLTO, the Cook County RTLO sets an explicit security deposit cap: landlords cannot collect more than one and one-half times the monthly rent. If a tenant's rent is $1,400 per month, the maximum security deposit is $2,100.
When the maximum deposit is charged, the tenant has the right to pay the additional half-month portion in installments over six months. Landlords must allow this payment structure when it's requested.
Return timeline: landlords have exactly 30 days after a tenancy ends to return the security deposit or provide an itemized statement of deductions for damages beyond normal wear and tear. Missing the 30-day deadline carries penalties.
Interest on deposits: for buildings with 25 or more units where deposits are held for more than six months, interest must be paid based on the rate of the largest Illinois commercial bank. In 2024, that rate was 0.005%. For smaller buildings, the interest requirement does not apply — but the deposit cap and return timeline still do.
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Late Fee Limits
The RTLO caps late fees differently from the Chicago RLTO. The suburban Cook County formula allows:
- A maximum flat fee of $10 for the first $1,000 of monthly rent, plus
- 5% of any rent above $1,000
On a $1,400 monthly rent, the maximum late fee is $30 ($10 for the first $1,000, plus 5% of the remaining $400). This is significantly lower than a standard $50-100 late fee that might appear on a generic lease form.
Charging more than this cap is an RTLO violation, not just a matter of enforceability — it exposes the landlord to affirmative claims from tenants.
Move-In Fees: The RTLO Closes the Chicago Loophole
Chicago investors developed the practice of charging non-refundable move-in fees as an alternative to security deposits, specifically to avoid RLTO deposit compliance obligations. The RTLO anticipated this workaround.
Under the RTLO, move-in fees charged to suburban Cook County tenants must be a "reasonable estimate" directly related to the actual cost of the tenant moving in — things like cleaning, administrative processing, or key duplication. They cannot function as undisclosed security deposits or general revenue. If a landlord charges a $500 "move-in fee" that does not correspond to any actual move-in cost, and a tenant challenges it, the landlord faces RTLO liability.
This distinction requires landlords to be specific and honest about what move-in fees cover. Document the actual costs and keep that documentation.
Required Lease Disclosures
Every lease covered by the RTLO must include a copy of the RTLO ordinance summary. The Cook County Commission on Human Rights publishes the official summary, which must be attached at signing.
Landlords who fail to attach the summary have a two-business-day right to cure once the deficiency is brought to their attention. If the cure period passes without compliance, the tenant has the right to terminate the lease. This is a meaningful penalty for an oversight that has nothing to do with the actual rental relationship.
How the RTLO Differs from the Chicago RLTO
Understanding where the two ordinances diverge matters for investors who own property on both sides of the city limits:
| Provision | Chicago RLTO | Cook County RTLO |
|---|---|---|
| Security deposit cap | No explicit cap | 1.5x monthly rent |
| Deposit interest rate | 0.01% (frozen since 2015) | Rate of largest IL bank (0.005% in 2024), buildings 25+ units only |
| Late fee formula | $10 per $500 + 5% of remainder | $10 per $1,000 + 5% of remainder |
| Move-in fees | Unregulated if non-refundable | Must reflect actual move-in costs |
| Owner-occupied exemption | Owner-occupied, 6 units or fewer | Owner-occupied, 6 units or fewer |
| Anti-lockout | Prohibited | Prohibited universally |
The RTLO is generally less punitive than the Chicago RLTO on deposit penalties, but it is far more restrictive than the absence of regulation that many suburban landlords assumed they were operating under.
Enforcement and Tenant Remedies
Tenants can raise RTLO violations as affirmative defenses in eviction proceedings. A landlord filing a nonpayment eviction against a tenant who can demonstrate RTLO violations faces the possibility of those violations being used to delay or complicate the proceeding.
Tenants may also pursue affirmative claims for RTLO violations independently of any eviction action. Consulting an attorney before filing eviction proceedings in suburban Cook County is not optional — it is how landlords avoid turning a $1,400 nonpayment case into a multi-month contested proceeding with potential attorney fee exposure.
Practical Steps for RTLO Compliance
- Use a lease reviewed by a Cook County landlord-tenant attorney, not a generic Illinois template
- Attach the official RTLO ordinance summary to every new lease and every renewal
- Document security deposit receipt, bank name and account location, in writing to the tenant
- Never charge a security deposit exceeding 1.5x monthly rent
- Set your late fee formula at or below the RTLO cap before anyone is ever late
- Structure any move-in fees with documented cost justification
- Return deposits within 30 days of tenancy end with itemized statements if deductions are made
The suburban Cook County landlord who discovers the RTLO through a tenant's attorney is in a significantly worse position than the one who complies from day one. The Illinois Investment Property Guide includes the full RTLO compliance checklist alongside the Chicago RLTO requirements, so investors operating across Cook County — city and suburbs — have a single reference covering both frameworks.
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