Illinois security deposit rules.
The Illinois rules for residential security deposits in plain English: how much can be charged, how fast it comes back, whether interest is owed, and what catches operators out.
Last reviewed · Statute: 765 ILCS 710/1 (Return Act); 765 ILCS 715 (Interest Act); Chicago RLTO § 5-12-080 · Not legal advice
How much can be charged
No statewide cap. Since January 1, 2024 (P.A. 103-224) the Return Act covers all residential lessors, not only those with five or more units. Chicago tenants have stronger local protections under RLTO.
When it has to come back
Within 30 days of move-out, an itemised statement of damage with paid receipts (or estimates, with paid receipts to follow within a further 30 days). Without a compliant statement, the full deposit is due within 45 days. There is no dollar threshold.
Interest
Required for lessors of 25 or more units in one building or a complex on contiguous parcels, on deposits held more than six months. The rate is the minimum-deposit passbook savings rate of the largest commercial bank with its main premises in Illinois, as of the December 31 before the lease (published annually by IDFPR; 0.005% for 2026).
Where the money has to sit
No statewide segregation rule. Chicago’s RLTO requires separate-account treatment for covered units.
What catches operators out
- Chicago RLTO is significantly stricter — covers most of the city and adds penalties.
- The 25-unit interest rule trips up portfolio operators who cross the threshold mid-year.
What this looks like with Standby in Illinois.
When a resident takes a Standby certificate there is no cash deposit to hold, so the cap, the return deadline and the interest rules above have nothing to attach to. You are covered up to the full deposit and draw on it when you need to.
When a resident pays cash instead, Standby handles that deposit under your lease and Illinois law, so your team is not tracking return deadlines by hand.
This page summarises the most common single-family and multifamily residential rule in Illinois. Furnished units, senior leases, mobile-home tenancies and short-term rentals can differ, and city ordinances may override the state default. Check the statute before relying on a figure for a specific lease.