Under Cook County rent increase laws, a landlord can raise your rent by any amount, but the increase is only enforceable if the landlord follows the rules on notice, delivery, and motive. Illinois blocks every local government from capping the dollar figure, so the fight, when there is one, is about process rather than price. The specific rules depend on whether your unit sits in suburban Cook County, Chicago, or Evanston, and some properties are exempt from the local ordinances entirely.
No Limit on the Dollar Amount
The Illinois Rent Control Preemption Act prohibits every unit of local government in the state, including home-rule municipalities, from enacting any ordinance that would control the amount of rent charged for private residential property.1Illinois General Assembly. 50 ILCS 825 – Rent Control Preemption Act2Illinois General Assembly. 50 ILCS 825 – Rent Control Preemption Act, Section 10 Your landlord can propose a $50 bump or a $500 bump. No county or city body can strike the number down for being too high. A rent increase that clears the procedural rules is enforceable regardless of how steep it feels.
The 60-Day Notice Rule in Suburban Cook County
The Cook County Residential Tenant and Landlord Ordinance (RTLO) requires at least 60 days’ written notice before a lease non-renewal or a change in lease terms takes effect.3Cook County Government. Residential Tenant Landlord Ordinance Raising the rent is a change in lease terms, so the 60-day clock runs whenever a landlord wants a higher rate at the start of a new lease period.
The notice should state the new monthly amount and the date it starts. Vague language about future “adjustments” without a dollar figure invites disputes. If the landlord fails to deliver proper written notice inside that window, the increase generally cannot take effect until 60 days have run from the date you actually received the notice.
During a fixed-term lease, a landlord usually cannot raise the rent at all unless the lease itself allows a mid-term increase. The 60-day requirement applies when the lease is ending and the landlord wants to renew at a higher rate. For month-to-month tenancies, Illinois state law otherwise requires only 30 days’ notice to change lease terms, but the RTLO’s 60 days overrides that shorter timeline for covered properties.4Illinois General Assembly. 735 ILCS 5/9-207
Whether the RTLO Actually Covers Your Unit
The RTLO covers rental housing across most of suburban Cook County, but three municipalities are excluded because they run their own ordinances: Chicago, Evanston, and Mount Prospect. If your unit is in one of those, the RTLO’s notice rules do not apply to you.
Several property types are exempt from most RTLO requirements even inside its geographic reach, though anti-lockout protections still apply:
- Owner-occupied buildings with six units or fewer where the owner lives on-site.
- A single-family home or condo unit, but only if it is the owner’s sole rental property, an owner or immediate family member lived there within the past 12 months, the owner personally manages the unit, and the owner is not a corporation.
- Medical and geriatric facilities, convents, monasteries, religious institutions, educational dormitories, and temporary or transitional shelters.
- Hotel and motel rooms, bed-and-breakfasts, rooming houses, and boardinghouses, unless a tenant has lived there for 32 or more continuous days and pays monthly rent.
- Shareholders in a cooperative apartment and buyers under a contract for deed.
- Employees whose housing is tied to their employment on the premises.
If your rental fits one of those categories, the RTLO’s notice requirements largely do not protect you, and your relationship with the landlord runs on the lease and general Illinois law.3Cook County Government. Residential Tenant Landlord Ordinance
How the Notice Has to Reach You
A well-worded notice is worthless if it isn’t delivered properly. The recognized methods are personal service, meaning handing it directly to the tenant or a responsible adult at the residence, and certified or registered mail, which creates a delivery date the tenant cannot reasonably dispute.
Slipping a note under the door or sending a text is risky. Electronic delivery may hold up only if the lease specifically authorizes it for official notices and both parties already use that method. When delivery is disputed, the landlord carries the burden of proving you received the notice.
Retaliation Is Presumed Within a Year
The RTLO bars landlords from using rent increases as payback against tenants who exercise their legal rights. Section 42-812 of the Cook County Code covers actions like reporting code violations, requesting legally required repairs, contacting a government agency about habitability, or joining a tenant organization.5Cook County. Residential Tenant Landlord Ordinance Summary
If a landlord raises rent within one year of any of those protected actions, the law presumes the increase is retaliatory. The landlord then has to show a legitimate, non-punitive reason for the higher price. A tenant who wins a retaliation claim can recover damages and attorney’s fees.5Cook County. Residential Tenant Landlord Ordinance Summary
Discrimination in Rent Adjustments
The Cook County Human Rights Ordinance makes it illegal to target specific tenants for higher or more frequent rent increases based on protected characteristics, including race, religion, disability, familial status, and source of income. The source-of-income protection matters here because it means a landlord cannot single out tenants who pay with Housing Choice Vouchers for steeper increases.
Complaints go to the Cook County Commission on Human Rights, which can impose fines and order compensatory damages. Tenants can also pursue claims in court. Rent adjustments must be based on the property and market conditions, not on who the tenant is.
Chicago’s Fair Notice Ordinance
Chicago sits outside the RTLO and has its own, stricter notice rules under the Fair Notice Ordinance. The required notice period depends on how long you have lived in the unit:
- Between six months and three years: at least 60 days’ written notice before the increase takes effect.
- Three years or more: 120 days’ written notice.
A Chicago landlord who fails to give the required notice cannot enforce the increase until the full period has run from the date of actual delivery.6City of Chicago. Know Your Rights: Fair Notice Ordinance
Evanston Has Its Own Rules
Evanston also falls outside the RTLO and runs its own Residential Landlord and Tenant Ordinance. Recent amendments require landlords to provide written notice of lease renewal at least 90 days before the current lease ends. The ordinance has been updated in recent years, so Evanston tenants should confirm the current notice periods with the city’s community development department.
Enforcing the Rules
One point that catches tenants off guard: the Cook County Commission on Human Rights does not enforce the RTLO. The ordinance is enforced entirely through private legal action, so a tenant who believes the notice rules were violated or that an increase was retaliatory has to file a lawsuit or work with a lawyer.3Cook County Government. Residential Tenant Landlord Ordinance Discrimination complaints under the Human Rights Ordinance do go through the Commission; RTLO procedural violations do not.
If a rent increase notice looks too short, retaliatory, or discriminatory, save the notice, write down the date you received it, and keep copies of any repair requests or complaints you have made. That documentation is what carries weight in front of a judge.
What Happens to Your Security Deposit
Under the RTLO, security deposits are capped at one and a half times the monthly rent.3Cook County Government. Residential Tenant Landlord Ordinance If rent goes up and the landlord wants the deposit to match, the new deposit still cannot exceed that ceiling. Any request for additional deposit money should arrive with the same written notice and detail as the rent increase itself.