Quick answer: Illinois sets no statewide maximum on a security deposit. The Security Deposit Return Act instead requires a landlord of five or more units to send an itemized statement with receipts within 30 days after the tenant vacates, or return the whole deposit within 45 days. A city ordinance may add limits.
This Illinois security deposit limit calculator applies 765 ILCS 710/1. Choose the size of the building and enter the rent and the total taken as security: it confirms there is no statewide cap, shows the deposit as months of rent and lists which rules apply. It does not check a lease or a local ordinance.
Illinois security deposit rules at a glance
| Rule | What Illinois says |
|---|---|
| Maximum amount | None under the statewide Act (765 ILCS 710/1) |
| Who is covered | Lessors of residential property with five or more units (710/1(a)) |
| Statement | Itemized, within 30 days after the tenant vacated, with paid receipts (710/1(a)) |
| No statement | The whole deposit within 45 days (710/1(a)) |
| Lease-set costs | A written lease may fix repair costs for damage beyond normal wear and tear (710/1(a)) |
| Penalty | Twice the deposit plus costs and fees for a refusing or bad-faith lessor (710/1(c)) |
| Interest | A separate Act is reported to cover 25 or more units |
| Local rules | Chicago and other cities may add limits |
How does the Illinois deposit law work?
- No state cap, but strict return rules. See the maximum security deposit in Illinois.
- Pet deposits and fees. See Illinois pet deposits and fees.
- First and last month and other up-front charges. See up-front charges when renting in Illinois.
What does this deposit calculator check?
Because there is no state cap, the calculator shows the total as months of rent for context rather than as a violation, tells you whether the statewide Act applies to a building of your size and notes whether the separate interest act is reported to apply. Because a deposit is money held to secure rent or compensate for damage, add every payment the landlord holds before you compare it with the rent, and ask for the total in writing, because the statewide Act sets no limit but the lease and a city ordinance may. It does not check Chicago’s ordinance or another local rule, which may set limits and notice periods of its own. When the deposit must come back is a separate question: see the Illinois security deposit return deadline calculator.
Examples of the Illinois deposit rules
| Monthly rent | Total security | Building | Result |
|---|---|---|---|
| $1,600 | $1,600 | Five or more units | No state cap; statement in 30 days |
| $1,600 | $4,800 | Five or more units | No state cap; three months |
| $1,600 | $3,200 | Four units | The state Act does not apply |
| $1,600 | $3,200 | 25 or more units | Interest Act reported to apply |
These examples show the arithmetic. They are not statements about a particular lease or landlord.
Related Illinois landlord-tenant calculators
These four calculators cover the same tenancy from different angles. From here you can go to the Illinois security deposit return deadline calculator for the date the landlord must refund or itemize the deposit, the Illinois eviction notice calculator for the notice period before a lease can end and the Illinois eviction timeline calculator for the earliest legal dates once an eviction case starts. Each one cites its own Illinois statutes and shows only what the law says.
Frequently asked questions
What is the maximum security deposit in Illinois?
The statewide statutes set none, although a city ordinance may.
Which landlords must follow the Security Deposit Return Act?
Lessors of residential property with five or more units.
When must an Illinois landlord return the deposit?
It must send an itemized statement with receipts within 30 days after the tenant vacated, or return the whole deposit within 45 days.
Does an Illinois landlord pay interest on a deposit?
A separate Act is reported to require it for buildings or complexes of 25 or more units; ask in writing.
Can a lease fix repair charges?
A written lease may specify costs for damage beyond normal wear and tear, and the statement must reference them.
Does Chicago have different rules?
Chicago and some other places have their own ordinances; check yours.