Landlord–tenant law in Illinois

What is distinctive about Illinois

• Deposits: 30 days, with a second tier at 45. Security Deposit Return Act applies to properties with 5 or more units. Itemised statement within 30 days; if none is furnished, the full deposit must be returned within 45 days.
• Late fees: uncapped by statute, so the limit is whatever a court would call reasonable. There is no mandatory grace period.
• Rent increases: 30 days, borrowed from the termination rule because Illinois has no rent-increase statute.

The mistake that costs the most here

Treating “no statutory cap” as no limit. A late fee in Illinoisis liquidated damages, and one set as a round percentage with no relation to the landlord’s actual cost is the kind of clause a judge strikes out.

Where these figures come from

Each rule above was read against the section it cites and the statutory wording is quoted on the dedicated page, so you can check it rather than take our word for it. That matters more than it sounds on this subject: when we read all 51 jurisdictions we found several widely-published figures to be wrong, including a Kentucky deposit deadline that does not exist, a South Dakota one reported as 14 days when the statute says 21, and late-fee caps for nine states that actually come from their self-storage statutes.

Local ordinances can add requirements the state does not, and statutes move — Washington, Connecticut, Nevada, Rhode Island and Maryland have all changed in the last three years. Each figure carries the date we read it.