Massachusetts Security Deposit Interest Calculator
This free Massachusetts security deposit interest calculator determines exactly how much interest your landlord owes you under Massachusetts General Laws Chapter 186, § 15B.
Security Deposit Details
Enter your original deposit amount and move-in date to calculate interest owed under Massachusetts law.
Leave blank to use the default estimate of 5.0%. Lesser of 5% or the actual bank interest rate earned on the deposit.
How Security Deposit Interest Works in Massachusetts
Deposit Details
Enter deposit amount and move-in date for calculation.
Compliance
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Your Claim
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Massachusetts Deposit Interest Rules
Legal basis: Massachusetts General Laws Chapter 186, § 15B. Last verified: 2026-05-25.
Key Details for Massachusetts
How Massachusetts Security Deposit Interest Works
Massachusetts requires landlords to pay interest on security deposits under M.G.L. c. 186, § 15B. The interest rate is the lesser of 5% or the actual interest rate earned on the bank account where the deposit is held. This cap of 5% was historically generous, but in today's low-rate environment, the actual bank rate is almost always the operative figure.
Interest must be paid annually — within 30 days of the anniversary of the tenancy. The deposit must be held in a separate, interest-bearing account at a Massachusetts bank, and the landlord must provide the tenant with a receipt showing the bank name, address, and account number.
Massachusetts has some of the most severe penalties for deposit violations in the country. Failure to comply with any provision of § 15B — including failing to pay annual interest, failing to provide a bank receipt, or commingling funds — entitles the tenant to the immediate return of the full deposit plus treble (3×) damages. Courts have enforced these penalties even for technical violations.
Example: MA Deposit Interest Calculation
Your deposit is $2,000 and you've been in the unit for 3 years. The bank pays 0.8% APY. The statutory cap is 5%.
Your landlord owes you $2,048.00, and should have been paying $16.00/year on each tenancy anniversary. If they haven't been paying annual interest, that violation alone may entitle you to treble (3×) damages — 3 × $2,000 = $6,000.
Frequently Asked Questions
What is the interest rate on security deposits in Massachusetts? ▼
The rate is the lesser of 5% or the actual interest rate earned by the bank account where your deposit is held. In practice, the bank rate is almost always lower than 5%, so you typically receive whatever the bank pays (often 0.5-2% APY currently). The 5% cap is a statutory maximum that was more relevant when bank rates were higher.
Does my Massachusetts landlord have to pay me deposit interest every year? ▼
Yes. Under § 15B, the landlord must pay you the accrued interest within 30 days of each anniversary of your tenancy — not just at move-out. If your landlord has never paid annual interest, they are in violation of the statute, which may entitle you to treble (3×) damages.
What happens if my landlord didn't give me a receipt for the deposit account? ▼
Under § 15B, the landlord must provide a written receipt with the bank name, address, and account number within 30 days of receiving the deposit. Failure to provide this receipt is a violation that can entitle you to the immediate return of the deposit plus treble (3×) damages — even if the landlord actually did deposit the money properly.
Can my Massachusetts landlord deduct an administrative fee from the interest? ▼
No. Unlike New York (which allows a 1% annual admin fee) or Pennsylvania (which also permits 1%), Massachusetts does not allow any administrative fee deduction. The tenant is entitled to the full interest earned on the account.
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