Short summaries of the rules that shape Illinois leases, notices, and deposit papers on LeaseGen.io. Last reviewed 2026-08-15. Not legal advice.
Security deposits
Cap
No statutory cap
Return clock
45 days after the tenancy ends
Illinois does not set a statewide maximum security deposit. Unused deposit plus an itemized list is generally due within 45 days (765 ILCS 710/1). Landlords with 25 or more units generally owe interest (765 ILCS 715). Chicago’s RLTO adds a 1.5× cap and a different clock.
A month-to-month tenancy generally takes 30 days’ written notice (735 ILCS 5/9-207).
Illinois does not prescribe a statewide 24-hour entry statute. Put a reasonable-notice entry clause in the lease. Chicago’s RLTO is stricter.
A Illinois rent increase should be in writing. Many landlords use at least the same notice they would use to end a month-to-month tenancy. A month-to-month tenancy generally takes 30 days’ written notice (735 ILCS 5/9-207). The lease may require more. Local rent-control rules can cap the amount even when the notice period is met.
These Illinois cities often have rent-control, just-cause, or relocation rules on top of state law. Confirm the ordinance before you raise rent or decline to renew.