Illinois security deposit rules: return deadlines and interest

The two deadlines

The Security Deposit Return Act gives a landlord two paths. Send an itemized statement of the damage within 30 days and you may keep the amounts on it. Send nothing and the whole deposit goes back within 45 days.

The Act doesn’t set a separate date for returning the balance after a statement. Sending the balance with the statement keeps both inside the 30 days.

Itemized statement

Within 30 days of the date the tenant vacated or the date the right of possession ends, whichever is later. It lists the damage allegedly caused and the estimated or actual cost to repair or replace each item, with paid receipts or copies attached. 765 ILCS 710/1(a)

Receipts after estimates

If the statement gave estimated costs, send the paid receipts within 30 days after that statement. If receipts can’t be had through no fault of the landlord, an itemized list of the costs with a verified statement takes their place. 765 ILCS 710/1(a), (b)

No statement sent

Return the deposit in full within 45 days of the date the tenant vacated. 765 ILCS 710/1(a)

How to deliver it

By hand, by postmarked mail to the tenant’s last known address, or by email to a verified address the tenant gave you. 765 ILCS 710/1(a)

What you can deduct

The statement covers property damage beyond normal wear and tear. Two details help small landlords.

Your own labor

If you do the repair yourself, you may include the reasonable cost of your labor. 765 ILCS 710/1(a)

Amounts set in the lease

Where the lease states a dollar amount for a kind of damage beyond normal wear and tear, you may withhold that amount. 765 ILCS 710/1(a)

Who the Act covers

Before 2024 the Act reached buildings with five or more units. Public Act 103-224 removed that line, so from January 1, 2024 it applies to any lessor of residential real property who has received a security deposit. A single rented house or condo is covered.

Coverage

All residential landlords who received a deposit. 765 ILCS 710/1; P.A. 103-224

Interest on deposits

Interest is a separate act with a higher threshold. It applies to a building, or a complex of buildings on contiguous parcels, with 25 or more units. Smaller properties outside Chicago and suburban Cook County owe no interest under state law.

The rate is the passbook savings rate of the largest Illinois commercial bank on December 31 of the year before the lease began. For leases that began in 2026 the state published 0.005%, so on a $1,500 deposit a year’s interest is about eight cents, under the $5 line where payment is required each year.

Which properties

25 or more units in one building or a complex on contiguous parcels. 765 ILCS 715/1

When interest starts

On any deposit held more than six months, computed from the date of the deposit. 765 ILCS 715/1

2026 rate

0.005%, published by the Illinois Department of Financial and Professional Regulation. IDFPR, security deposit interest rate for 2026

When to pay it

Within 30 days after the end of each 12-month rental period, in cash or as a rent credit, when the interest is $5 or more. Not required while the tenant is in default. All unpaid interest is due when the tenancy ends. 765 ILCS 715/2

Public housing

Not covered by the interest act. 765 ILCS 715/3

Penalties

Both acts carry penalties that are larger than the deposit itself.

Return Act

Twice the amount of the deposit due, plus court costs and reasonable attorney’s fees. Applies when a court finds the landlord refused to send the statement or sent it in bad faith, and didn’t return the deposit on time. 765 ILCS 710/1(c)

Interest Act

An amount equal to the deposit, plus court costs and reasonable attorney’s fees, for a willful failure to pay interest. 765 ILCS 715/2

Chicago and suburban Cook County add their own rules

Two local ordinances go further than state law for the units they cover. Chicago’s Residential Landlord and Tenant Ordinance requires a separate insured Illinois account, a receipt and yearly interest, with a penalty of two times the deposit plus interest. Our Chicago guide walks through it.

The Cook County Residential Tenant and Landlord Ordinance, for covered rentals outside Chicago, limits a deposit to one and a half months’ rent and gives 30 days after move-out to return it.

Chicago

Return within 45 days after the tenant vacates; separate account, receipt and interest rules. Chicago Mun. Code § 5-12-080

Suburban Cook County

Deposit of no more than one and a half months’ rent; return within 30 days after the tenant has vacated. Cook County Code § 42-111