The Illinois Department of Financial and Professional Regulation, Division of Banking, has announced that the interest rate paid by the largest commercial bank in Illinois on minimum deposit savings accounts as of December 31, 2025, was 0.005% with an Annual Percentage Yield (APY) of 0.01%.
This figure is relevant for landlords under the Security Deposit Interest Act (765 ILCS 715), which requires lessors of residential properties with at least 25 units to pay interest on security deposits held for six months or longer. The law mandates that this interest must be paid either in cash or as a credit toward rent within 30 days after each 12-month rental period ends. The applicable rate matches the interest paid by the state’s largest commercial bank on minimum deposit passbook savings accounts as of December 31 in the previous calendar year.
There are some exceptions: public housing deposits and lessees who are in default under their lease terms are not covered by this act.
The Northern Trust Company, based in Chicago, was identified as the largest commercial bank with its main banking premises in Illinois as of December 31, 2025.
The Illinois Department of Financial and Professional Regulation is responsible for protecting consumers and supporting career opportunities in financial and professional services. More about its mission can be found on its official mission page. The department also works to safeguard residents, maintain stable financial institutions, license qualified professionals, and support state commerce as described on its official website. Operating statewide since its establishment in 2004 through the consolidation of several agencies—including the Office of Banks and Real Estate—the department regulates banks and professionals across Illinois (official history page). It oversees sectors such as banking, real estate, healthcare licensing, and other professional activities (official website).
For further details about landlord obligations under this statute, individuals are encouraged to review the Security Deposit Interest Act.
