Can a Illinois landlord raise rent more than once a year?

It depends on the tenancy type and any applicable rent control. On a month-to-month tenancy, a Illinois landlord can technically issue multiple rent increases in one year, each with the proper 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.). However, in jurisdictions with rent caps (California's AB 1482, Washington's HB 1217, New York's Good Cause coverage), the annual cap applies regardless of how many increase notices are issued. So even if a landlord delivers two increase notices in 12 months, the combined increase cannot exceed the statutory annual cap. On a fixed-term lease, no increase is permitted during the term unless the lease itself authorizes it, regardless of state. After the term ends, the landlord can issue an increase as part of the renewal offer.

Source: Lease-based; 735 ILCS 5/9-207 (30-day month-to-month termination default)