Illinois Security Deposit Interest: What You Are Owed

Illinois requires a landlord to pay interest on a residential security deposit — the passbook savings rate at the largest commercial bank in Illinois under 765 ILCS 715/1. Buildings with 25 or more units, on deposits held more than 6 months.

Last updated: September 2026 · Rule verified September 11, 2026

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The short answer: yes. Illinois requires deposit interest at the passbook savings rate at the largest commercial bank in Illinois, under 765 ILCS 715/1, verified September 11, 2026. This rate is reset every year, so the figure above is stamped with its year and the official rate page carries the current one.

The 25-unit threshold means most Illinois renters are not covered by the state statute. Chicago is the significant exception — the city ordinance applies to far smaller buildings and sets its own rate.

What the Illinois Rule Requires

Ratethe passbook savings rate at the largest commercial bank in Illinois — the rate paid by the largest commercial bank in Illinois by total assets on minimum deposit passbook savings accounts, as of December 31 of the year before the tenancy began. Republished each year by Illinois Department of Financial and Professional Regulation publishes the applicable rates each year: current rate.
Who it coversBuildings with 25 or more units, on deposits held more than 6 months.
When it is paidWithin 30 days after the end of each 12-month rental period, once accrued interest reaches $5 or more, in cash or as a credit against rent.
Deposit return deadlineSet by the separate deposit-return statute; the interest obligation runs on the 12-month cycle above.
Statute765 ILCS 715/1
VerifiedSeptember 11, 2026

Laws change and indexed rates change annually. The figures above reflect the sources as read on September 11, 2026, and each link goes to the official text so the current version can be checked directly.

Illinois Security Deposit Interest Calculator

Set to Illinois. Switch jurisdictions in the dropdown to compare.

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Set automatically where the jurisdiction publishes a rate. Where it follows a bank account, enter the rate from the statement.

Most statutes specify simple interest

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What Illinois Deposit Interest Works Out To

Illinois does not publish a single rate — it is the passbook savings rate at the largest commercial bank in Illinois — so there is no fixed table to print. The calculator above takes whatever rate applies to the account and shows what it produces over the holding period. The rate usually appears on the annual statement or the notice naming the bank where the deposit sits.

City Ordinances in Illinois

Chicago

The Chicago RLTO reaches far smaller buildings than the 25-unit state statute, so a Chicago renter is usually covered by the ordinance rather than by 765 ILCS 715. The rate is 0.01% for 2026, set by Chicago City Comptroller, announced on the first business day of each year under Chicago Muni. Code § 5-12-081. Because it is reset annually, the figure here carries its year — the City of Chicago — Security Deposit Interest Rates publishes the current one.

When the Interest Is Never Paid

Deposit interest is one of the more commonly overlooked obligations in residential tenancy, partly because the amounts are small enough that neither side tracks them and partly because it is often owed annually while the deposit itself only comes up at move-out. A tenant who has never received an interest payment or an annual statement has usually not been told the obligation exists.

What tends to matter is documentation rather than argument. The lease records the deposit amount and the date it was paid. Bank records show when it cleared. The statute supplies the rate and the schedule, and the arithmetic follows from those three things. Where a landlord is required to give an annual statement naming the bank and the interest payable, the absence of that statement is itself part of the record.

How Illinois Compares to Nearby States

Deposit interest is one of the sharpest state-line differences in residential tenancy: neighboring states frequently land on opposite sides of it.

StateInterest required?RateSource
WisconsinNo
IowaYesnone for the first five years — that interest belongs to the landlordIowa Code § 562A.12(2)
MissouriNo
IndianaNo

The full picture across all 51 jurisdictions is on the deposit interest by state index.

Common Questions About Illinois Deposit Interest

Does my landlord have to pay interest on my security deposit in Illinois?

Yes. Illinois requires it under 765 ILCS 715/1, verified as of September 11, 2026. Buildings with 25 or more units, on deposits held more than 6 months. The rate is the passbook savings rate at the largest commercial bank in Illinois. Within 30 days after the end of each 12-month rental period, once accrued interest reaches $5 or more, in cash or as a credit against rent.

How much interest is a security deposit worth in Illinois?

Illinois does not set a single published percentage — the rate is the passbook savings rate at the largest commercial bank in Illinois, so the amount depends on the account the deposit is held in. The calculator on this page takes a rate and shows what it produces across a range of deposit sizes and holding periods.

When does a Illinois landlord have to pay the interest?

Within 30 days after the end of each 12-month rental period, once accrued interest reaches $5 or more, in cash or as a credit against rent. The deposit itself is subject to a separate deadline: Set by the separate deposit-return statute; the interest obligation runs on the 12-month cycle above.

What is unusual about the Illinois rule?

The 25-unit threshold means most Illinois renters are not covered by the state statute. Chicago is the significant exception — the city ordinance applies to far smaller buildings and sets its own rate.

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