Illinois security deposit law: the 30/45-day rules, and the 2024 change

The two clocks

Under the Act (765 ILCS 710), if you want to keep any of the deposit for damage, you must send an itemized statement within 30 days of the tenant vacating (or their right of possession ending, whichever is later) — listing each item of damage and its actual or estimated repair cost. Delivery can be personal, by mail to their last known address, or by email to a verified address the tenant gave you. If you sent estimates, the paid receipts must follow within 30 days of the statement. Skip the statement and receipts, and the full deposit is due back within 45 days of move-out.

Since the 2024 amendments, a written lease may also pre-specify cleaning or replacement costs for particular components — those specified amounts can be withheld if the statement references the lease and attaches the relevant portion, and the costs must reflect damage beyond normal wear and tear. Your own labor can be billed at a reasonable cost.

What violations cost

A landlord who refuses to supply the itemized statement, supplies it in bad faith, or fails to return what's owed on time is liable for twice the deposit, plus court costs and attorney's fees (765 ILCS 710/1(c)). One procedural mercy: if the tenant never gave you a mailing or email address, the statute doesn't hold you liable for failing to reach them — but collect a forwarding address at move-out anyway; it starts every clock cleanly.

The interest rule (bigger buildings only)

A separate statute — the Security Deposit Interest Act, 765 ILCS 715 — requires interest on deposits held more than six months, but only for landlords with 25 or more units in one building or a contiguous complex. The rate is pegged to the passbook savings rate of the state's largest bank, and accumulated interest of $5 or more is paid or credited to rent within 30 days after each 12-month rental period. Small landlords: this one genuinely doesn't apply to you.

Where state law is NOT the rulebook

• Chicago: the Residential Landlord and Tenant Ordinance (RLTO) has its own, stricter deposit regime — receipts, separate accounts, its own interest and penalty rules. Chicago landlords should read the ordinance, not this page.
• Suburban Cook County: the Cook County RTLO (2021) covers most suburbs inside Cook — Evanston and Oak Park also have their own ordinances.
• DuPage, Will, Kane, and the rest of the state: state law is the rulebook. Naperville, for instance, adds no deposit rules of its own — see our Naperville guide.

Also worth knowing: Illinois sets no cap on how much deposit you can collect (market practice is one month), and if you sell the building, deposit liability follows the property — buyer and seller are jointly liable until it's properly transferred.

The compliance habit that makes this easy

Every dispute in this area comes down to dates and documentation: when the tenancy ended, what was damaged, what it cost, when you sent the statement. That's a record-keeping problem before it's a legal one. The Illinois deadline page is the quick-reference card, the deposit return letter produces the itemized statement, and a free RentChime account tracks lease end dates so the 30-day clock never starts without you noticing.