Outside of Chicago, the general rule for tenants who live in buildings with 24 or fewer apartments, the landlord does not have to pay interest on the security deposit. But, if the landlord owns buildings right next to the building (like in the same complex) and the total number of apartments between the buildings adds up to 25 or more apartments, then the landlord must pay interest. For a building with 25 or more apartments, the landlord must pay interest on the security deposit. In Chicago, all landlords must pay interest on security deposits, unless the building has 6 or less units and is owner-occupied.

The landlord is required to pay interest if they have held the security deposit for 6 or more months. If the tenant stays in the apartment 12 or more months after they signed their first lease, the landlord can choose between paying the interest on the security deposit or reducing the rent for one month by the amount of interest owed. After the tenant moves out, the landlord must pay them all the interest owed within 30 days.

To figure out how much interest a landlord owes, multiply the security deposit amount by the number in the table below.