Illinois Rent Increase Laws: The Landlord and Tenant Guide

Illinois is a free-market rent state with a twist. There is no statutory cap on how much a landlord may raise the rent, and local rent control is preempted statewide, so no Illinois city may impose one either. But “no cap” is not “no rules.” The tenancy type controls when you may raise rent at all, a month-to-month increase rides on the 30-day termination notice under section 9-207 of the Code of Civil Procedure, and Chicago, Cook County, and Evanston layer on much longer, tiered notice requirements. On top of all of that sit the Landlord Retaliation Act and source-of-income protections. Get the timing and the notice right and your increase holds; miss one and a tenant can refuse the new rent and use the defect against you.

The stakes are practical. An increase served on the wrong notice, imposed mid-term without authority, or timed to punish a tenant is not just risky — it is unenforceable, and an improper increase can become a tenant defense if you later try to evict for nonpayment of the raised rent under the Illinois eviction notice rules. Because local ordinances change on their own schedules and the statewide preemption is under active legislative debate, treat every rule in this guide as a starting point and verify the current law for your county and city before you serve anything.

Below, a detailed overview video summarizes the Illinois framework; the sections that follow break down each piece — why there is no cap, the statewide preemption of rent control, when you may raise rent at all, the statewide 30-day notice mechanism, the Chicago Fair Notice tiers, the Cook County and Evanston overlays, retaliation and source-of-income limits, and a step-by-step landlord playbook — plus an Illinois-specific FAQ.

The starting point for Illinois rent-increase law is what the state does not do: it imposes no statutory cap on how much or how often a landlord may raise the rent. There is no percentage ceiling like California’s 5-percent-plus-inflation formula and no annual limit tied to a price index. For housing that is not inside a special program, the dollar figure on a lawful increase is set by the landlord and the market, not by a statute.

That does not mean anything goes. Three separate limits survive the absence of a cap, and every lawful Illinois increase has to clear all three: the tenancy type decides whether you may raise the rent at this moment at all; the notice the tenancy or the local ordinance requires decides how far ahead you must act; and the bars on retaliation and discrimination decide whether an otherwise-valid increase is nonetheless unlawful because of why or how it was imposed. The rest of this guide walks each of the three.

Illinois goes a step further than simply declining to set a cap: it forbids its own cities and counties from setting one. The Rent Control Preemption Act, codified at 50 ILCS 825, provides that a unit of local government may not enact, maintain, or enforce an ordinance or resolution that would control the amount of rent charged for leasing private residential or commercial property. In plain terms, no Illinois municipality — not Chicago, not any suburb — may lawfully impose rent control while the Act stands.

This is the single most misunderstood point in Illinois rent law, and it is where the older version of this page was simply wrong. Claims circulate online that the preemption was “repealed” — that is not correct. As of this update, the Rent Control Preemption Act remains in force. It has never been repealed.

The practical consequence for a landlord is straightforward: outside of a special affordable-housing program, no local government in Illinois can tell you the maximum rent or the maximum increase. What local governments can and do regulate is the process — chiefly how much notice you must give before an increase or a non-renewal — which is exactly what Chicago, Cook County, and Evanston have done. Those are notice rules, not caps, and they are covered below.

The absence of a cap only matters once you actually have the right to change the rent. That right depends entirely on the tenancy.

During a Fixed-Term Lease: Generally Locked

While a fixed-term lease is running, the rent is set at the agreed amount for the whole term. You cannot raise it mid-term unless the lease itself contains an explicit escalation clause that permits the change. Absent that clause, the tenant is entitled to the agreed rent through the end of the term, and a purported mid-lease increase is unenforceable no matter how it is served. The ordinary time to reset the rent on a fixed-term tenant is at renewal, when a new term begins; if the tenant instead wants to leave early, that is governed separately by the Illinois lease termination rules.

On a Month-to-Month Tenancy: Going Forward With Notice

A month-to-month tenancy is where most Illinois increases happen. Here the landlord changes the rent going forward, and the change takes effect only after the required notice period runs. Because Illinois has no statute that names a notice period for a rent increase as such, the notice is borrowed from the termination rule: the landlord offers the new rent and, if the tenant will not agree, may end the tenancy on the statutory notice. That mechanism is the next section.

Illinois has no rent-increase-specific notice statute. What it has is a termination-notice statute, and that is what governs a month-to-month increase in practice. Under section 9-207 of the Code of Civil Procedure, 735 ILCS 5/9-207, a landlord may terminate a tenancy from month to month by giving at least 30 days’ written notice, and a week-to-week tenancy on at least 7 days’ written notice; a separate section, 735 ILCS 5/9-205, requires at least 60 days’ written notice to end a tenancy from year to year.

Because there is no separate rent-increase clock, the 30-day termination notice is the practical floor for raising rent on a month-to-month tenant: the landlord proposes the new rent, and if the tenant will not accept it, the landlord may end the tenancy on that notice. The tenant then either agrees to the new rent and stays, or the tenancy ends. The 30 days must be measured to the rent period — a notice meant to make a new rent effective on the first of a month generally has to be served at least 30 days before that date.

What a Proper Notice Contains and How to Serve It

A defensible Illinois rent-increase notice is in writing and states, at minimum, the tenant’s name and the property address, the current rent, the new rent, and the effective date, with enough lead time to satisfy section 9-207 and any local ordinance. A verbal announcement, or a text the tenant never agreed to accept as a delivery method, does not reliably change the rent, and the old rent continues until proper notice is given. Serve it by a provable method — certified mail with return receipt, or personal delivery with a signed acknowledgment — and keep a copy of both the notice and the proof of delivery.

Chicago is the biggest local overlay in the state. The city’s Residential Landlord and Tenant Ordinance, as amended by the Fair Notice provisions at section 5-12-130 of the Municipal Code, requires tiered advance written notice before a landlord raises the rent or declines to renew a lease. The tier is set by how long the tenant has continuously lived in the unit, and the longer the tenancy, the more notice you owe.

The same three tiers govern both a rent increase and a decision not to renew — the city treats them as the same category of change that a tenant deserves time to plan around. The tiers reach broadly across Chicago rentals, and coverage can include smaller and owner-occupied buildings that the older RLTO exempted, so do not assume a small building is outside the rule. Confirm current coverage for the specific property.

Chicago is not the only Illinois jurisdiction with its own notice rules, and the rules do not overlap — each jurisdiction has one governing ordinance, so the first task for any suburban Cook County property is to figure out which one applies.

The Cook County RTLO

Suburban Cook County has its own Residential Tenant and Landlord Ordinance (the RTLO), which covers unincorporated areas and many suburbs that have not opted out. Its notice structure differs from Chicago’s tiers: rather than a 30-60-120 ladder, the RTLO generally requires a flat 60 days’ written notice before a rent increase or a non-renewal, with a longer period available to the tenant if the landlord gives short notice. Critically, the Cook County RTLO does not apply inside the City of Chicago, in Evanston, or in Mount Prospect, because each of those has its own ordinance.

Evanston and Home-Rule Municipalities

Evanston is one example of a home-rule municipality that runs its own landlord-tenant ordinance instead of Chicago’s or the county’s, with its own notice requirements. Other home-rule cities and villages around the state may have adopted local notice rules as well. None of these ordinances may cap the rent — the statewide preemption forbids that — but they can and do set longer notice periods and extra procedures for a lawful increase.

Even with no cap and a short statewide notice, an increase that clears those hurdles can still be unlawful if it is retaliatory. Illinois modernized this area recently: the old Retaliatory Eviction Act was repealed and replaced, effective January 1, 2025, by the Landlord Retaliation Act, 765 ILCS 721. The new Act is broader than the one it replaced, and it names rent increases specifically.

What Counts as Protected Activity

Under the Landlord Retaliation Act, a landlord may not raise rent, terminate or refuse to renew a tenancy, or reduce services in retaliation for a tenant’s protected activity. Protected activity is defined broadly and includes complaining to a government agency about a building or health code violation, requesting a repair the law or the lease requires, contacting or seeking help from a community organization, testifying in a proceeding about the condition of the premises, and organizing or joining a tenants’ union. This is a meaningful expansion over the repealed Act, which reached a narrower set of complaints.

The One-Year Presumption and the Remedies

The Act creates a rebuttable presumption: if the landlord’s adverse action — including a rent increase — occurs within one year after the tenant’s protected activity, retaliation is presumed, and the burden shifts to the landlord to prove a legitimate, non-retaliatory business reason. A tenant who proves retaliation may recover an amount equal to the greater of two months’ rent or two times the damages sustained, plus reasonable attorney’s fees, along with relief such as terminating the lease and recovering possession. The safest practice is to time increases to the ordinary schedule and to document the market and cost reasons behind the number, so a routine increase never looks like a reprisal.

A rent increase, like any rental decision, cannot be used to discriminate. Beyond the retaliation bar, two overlapping fair-housing regimes apply to every Illinois landlord within their scope.

Protected Classes

An increase cannot target a protected class under the federal Fair Housing Act and the Illinois Human Rights Act, 775 ILCS 5 — including race, color, religion, national origin, sex, familial status, disability, and the additional classes Illinois recognizes. Setting a steeper increase, or a different schedule, for one tenant because of a protected characteristic is housing discrimination even where the number itself would otherwise be lawful.

Source of Income Is Now Protected Statewide

Since January 1, 2023, the Illinois Human Rights Act protects source of income as a class, which for renters means a landlord subject to the Act generally may not refuse to rent to, or set different rent or terms for, a tenant because they intend to pay with a Housing Choice Voucher (Section 8) or other lawful rental assistance. Raising or setting rent to push out or exclude a voucher holder, or advertising that vouchers are not accepted, can be source-of-income discrimination. Narrow exemptions exist — certain owner-occupied buildings, for example — so confirm whether the Act reaches your property before assuming you may treat voucher income differently.

Put the whole framework into a repeatable sequence and a rent increase becomes routine instead of risky. Follow these steps every time.