Illinois Rent Increase Rules for Landlords

Illinois has no limit on how much a landlord can raise the rent, because the Rent Control Preemption Act (50 ILCS 825) bars every city and county, including Chicago, from controlling rent amounts. The rules that apply are about timing: under a fixed-term lease you wait until the lease ends unless it expressly allows an earlier increase, and for a month-to-month tenant you give at least 30 days' written notice unless local rules require more. In Chicago, the notice period is 30, 60, or 120 days depending on how long the tenant has lived in the unit.

Can an Illinois city or county cap rent increases?

No. The Rent Control Preemption Act says a unit of local government may not enact, maintain, or enforce an ordinance that would have the effect of controlling the amount of rent charged for private residential or commercial property. A separate section of the Act denies home rule cities, which otherwise have broad local powers, the power to regulate rent amounts. The Act has been in effect since 1997 and has not been repealed as of October 2026.

Local governments can still regulate how and when a rent increase happens, and Chicago and Cook County both do.

When can you raise the rent?

The answer depends on the type of tenancy:

Evanston's ordinance, effective January 1, 2025, requires 90 days' notice of proposed rent increases.

The Illinois Attorney General's tenant guide gives 30 days' notice as the general rule for month-to-month rent increases. Oak Park's landlord-tenant guidance confirms that a lease can expressly authorize rent changes during its term. The 30-day figure matches the state eviction law, 735 ILCS 5/9-207, which lets a landlord end a month-to-month tenancy with 30 days' written notice, subject to longer local notice requirements. If the tenant will not accept the new rent, that termination notice is the next step.

Time the notice to the rent due date. Where the 30-day rule applies, to start a higher rent on December 1, deliver the notice no later than November 1, and earlier if you are not handing it over in person.

The state eviction law accepts these methods for serving a notice: handing it to the tenant, leaving it with a person 13 or older who lives at the unit, or sending it by certified or registered mail with a returned receipt from the addressee.

What does Chicago require?

Chicago's Residential Landlord and Tenant Ordinance includes the Fair Notice rules in Municipal Code section 5-12-130(j). Before the stated end date of the rental agreement, you must give written notice of an intent to raise the rent, to end a month-to-month tenancy, or not to renew a lease:

These periods apply to written leases and informal month-to-month arrangements alike. They also apply in owner-occupied buildings with six or fewer units, which are otherwise exempt from most of the Chicago ordinance, because the 2020 Fair Notice amendment made section 5-12-130(j) apply to every rented unit in those buildings.

Worked example: a tenant who has lived in the unit for four years has a lease ending June 30, 2027. To raise the rent starting July 1, 2027, deliver written notice by March 2, 2027, which is 120 days before June 30.

If the notice is late, missing, or defective, the tenant may stay for up to 60 days (for tenancies of three years or less) or 120 days (for tenancies over three years) after the date the notice was given, or the date it should have been given, at the old rent and terms. An amendment passed April 15, 2026 adds that you must wait out that period before filing an eviction case. If you file early, the tenant can raise the faulty notice as a defense, and you cannot recover possession until the period ends.

What about suburban Cook County?

Cook County's Residential Tenant Landlord Ordinance (RTLO) covers most rentals in Cook County outside towns that have their own landlord-tenant ordinance, such as Chicago. It does not set a separate rent increase notice. It does require at least 60 days' written notice before the end of the rental agreement to end a month-to-month tenancy or not renew a lease. If you skip that notice, the tenant can stay up to 120 days after notice is finally given, on the same terms as the last month.

The RTLO also bars requiring a tenant to commit to a renewal more than 60 days before the lease ends, with a penalty of one month's rent or actual damages, whichever is greater. In practice, send the renewal offer with the new rent at least 60 days before the lease ends and do not demand an answer sooner. The RTLO does not cover owner-occupied buildings with six or fewer units, or a single-family home or condo that is the owner's only rental, that the owner or an immediate family member lived in for at least a month in the 12 months before marketing the property, that the owner manages personally, and that is not owned by a corporation.

Can a rent increase be retaliation?

Yes. The Illinois Landlord Retaliation Act, effective January 1, 2025, bars a landlord from knowingly raising rent, cutting services, refusing to renew, or ending a tenancy because the tenant in good faith complained to a code enforcement agency, asked for repairs required by code or the lease, joined a tenants' union, testified about the property's condition, or used another legal right.

If the tenant's protected activity happened within one year before the increase, a court presumes the increase was retaliatory. You can overcome that presumption by proving a legitimate, non-retaliatory reason for the increase, or that you started the increase before the tenant acted. A tenant who proves retaliation can recover the greater of two months' rent or twice the actual damages, plus attorney's fees. Keep records of how you set each renewal rent.

For the termination step if a tenant will not pay the new rent, see ending a month-to-month rental agreement and the Illinois eviction process. Repair requests are a common protected activity, so match increases against your Illinois repair obligations, and for wording a notice in any state, see how to increase the rent.