Can a Illinois landlord raise rent at any time?
No. A Illinois landlord cannot raise rent during a fixed-term lease (unless the lease itself provides for it). On a month-to-month tenancy or after a fixed term expires, the landlord may raise rent with the required advance written notice. Illinois has no statewide advance notice specific to rent increases. 735 ILCS 5/9-207 sets 30 days as the month-to-month termination default, which landlords treat as the minimum for rent changes. No state rent cap; local rent control is preempted statewide. Any increase served without the correct notice period, or that exceeds the applicable cap, is void.
Source: Lease-based; 735 ILCS 5/9-207 (30-day month-to-month termination default)
This is an informational answer based on Lease-based; 735 ILCS 5/9-207 (30-day month-to-month termination default) as of early 2026. It is not legal advice. Housing law changes year to year and local ordinances (especially in rent-controlled or rent-stabilized cities) can override or add to state law. For contested cases, consult a Illinois-licensed attorney.