Illinois security deposit interest
The Illinois Security Deposit Interest Act applies only to landlords of 25 or more units in the same building or complex, and only when the deposit is held more than six months. The rate is whatever the largest commercial bank in Illinois paid on minimum-deposit passbook savings accounts on 31 December of the previous year. For 2026 that is 0.005%.
Print this page for a dated statement showing the rate applied to each year and the statute.
How Illinois deposit interest works
Chicago has its own, stricter ordinance with a separately published rate and applies to far smaller buildings; if the unit is in Chicago, use the Chicago page. Suburban Cook County also has an ordinance of its own.
The rules in brief
- Applies to 25 or more units in one building or in a complex of contiguous buildings.
- Interest is due within 30 days after the end of each 12-month rental period, paid in cash or credited against rent, unless the tenant is in default.
- A landlord who wilfully fails to pay owes the tenant an amount equal to the whole deposit plus court costs and attorney fees.
Illinois Department of Financial and Professional Regulation. Each January, based on the largest Illinois commercial bank’s minimum-deposit passbook savings rate on 31 December.
Illinois deposit interest rate history
The calculator uses the rate for each calendar year automatically when the rate field is left at the published figure.
| Year | Rate | Interest on $1,000 for the year |
|---|---|---|
| 2026 | 0.005% | $0.05 |
| 2025 | 0.005% | $0.05 |
| 2024 | 0.005% | $0.05 |
| 2023 | 0.005% | $0.05 |
| 2022 | 0.005% | $0.05 |
| 2021 | 0.005% | $0.05 |
| 2020 | 0.005% | $0.05 |
| 2019 | 0.005% | $0.05 |
| 2018 | 0.005% | $0.05 |
| 2017 | 0.005% | $0.05 |
| 2016 | 0.045% | $0.45 |
Source: Illinois Department of Financial and Professional Regulation.
Worked examples: one year held
At the current rate, for a deposit paid on 1 January 2025 and returned on 1 January 2026.
| Deposit | Interest-bearing portion | Interest owed |
|---|---|---|
| $1,000.00 | $1,000.00 | $0.05 |
| $1,500.00 | $1,500.00 | $0.08 |
| $2,500.00 | $2,500.00 | $0.13 |
Other Illinois deposit rules
- Maximum deposit: No statutory limit (statewide); local ordinances such as the Chicago RLTO and Cook County RTLO impose their own rules.
- Return deadline: Itemized statement of damages (with paid receipts or estimates) within 30 days after the tenant vacates or the right of possession ends, whichever is later; if no compliant statement is furnished, the full deposit must be returned within 45 days after the tenant vacates. Landlord is not liable if the tenant never supplies a mailing or e-mail address..
- Late fees: No statewide statutory cap or grace period; no statute located. Late fees must be in the lease and reasonable (unenforceable penalty if excessive). The Landlord and Tenant Act (765 ILCS 705) was read in full and contains no late-fee section. The frequently cited '$20 or 20% of monthly rent, whichever is greater' rule is from the Self-Service Storage Facility Act (770 ILCS 95) and does not apply to residential rentals. Chicago (RLTO) and Cook County (RTLO) ordinances impose local caps and grace periods.
Full page: Illinois landlord and tenant rules.
Frequently asked questions
Does Illinois require deposit interest for small landlords?
No. Outside Chicago and suburban Cook County, only landlords with 25 or more units in a building or complex must pay interest.
What is the 2026 Illinois deposit interest rate?
0.005%, the passbook rate of the largest Illinois bank on 31 December 2025, as published by IDFPR.
I live in Chicago. Which rate applies?
The Chicago RLTO rate (0.01% for 2026) and the Chicago rules, which cover most buildings except owner-occupied ones with six or fewer units.