Guide
Landlord Didn't Return Your Security Deposit Within 30 Days? What Massachusetts Law Says
The 30-day deadline is the sharpest edge in Massachusetts security deposit law. If your tenancy has ended and more than 30 days have passed without your deposit, or the balance you're owed, coming back, M.G.L. c. 186, §15B gives you real leverage. Here's how the rule works and what to do next.
The 30-day rule
Under §15B(4), your landlord must return your security deposit, minus any lawful deductions, within 30 days after the end of your tenancy. Lawful deductions are limited: unpaid rent, unpaid real estate tax increases you agreed to in the lease, and the cost to repair damage beyond reasonable wear and tear. Damage deductions only count if you received an itemized list, sworn under pains and penalties of perjury, within that same 30-day window.
These are calendar days, not business days, and the clock starts when your tenancy ends, typically your lease end date or the agreed move-out date.
What counts as the end of your tenancy?
For a fixed lease, it's usually the lease's end date. For month-to-month tenancies, it's the date the tenancy was properly terminated, for example the end of the rental period named in a 30-day notice to quit. If you moved out early but the lease ran on, the question can get more complicated; the safest reference point is the date the tenancy legally ended, not just the day you handed back the keys.
What happens when the deadline is missed
Failing to return the balance you're owed within 30 days is one of the specific violations, §15B(6)(e), that forfeits the landlord's right to keep any part of the deposit. It's also one of the violations that can trigger the statute's strongest remedy: under §15B(7), a court may award three times the amount wrongfully withheld, plus 5% interest from when payment became due, plus court costs and reasonable attorney's fees.
That combination is why a well-documented demand letter often gets results: the downside for a landlord who ignores it can be much larger than the deposit itself.
What if the landlord returned part of it?
A partial refund doesn't reset anything. Whatever balance you're lawfully owed is still due within 30 days. If deductions were taken without a timely, sworn, itemized list, or for things that are really ordinary wear and tear, those deductions may not hold up, and the remaining balance may still be recoverable with the same §15B(7) exposure.
What to do now
Start with a written demand letter: state the facts, cite §15B(4), §15B(6)(e), and §15B(7), name the amount, and give a 10-business-day deadline. Send it certified mail with return receipt. If the deadline passes, Massachusetts small claims court handles exactly this kind of case, and no lawyer is required.
Frequently asked questions
Does the 30-day deadline include weekends and holidays?
The statute counts 30 days from the end of the tenancy without carving out weekends or holidays, so treat it as calendar days.
My landlord offered a partial refund. Should I take it?
That's your call. Accepting a partial payment doesn't automatically waive your right to pursue the rest, but be careful about signing anything that releases your claims. The balance you're lawfully owed remains due.
Can I really recover three times my deposit?
The statute may allow treble damages on the amount wrongfully withheld when the 30-day return rule is violated, plus interest, court costs, and attorney's fees under §15B(7). Whether that applies depends on the specific facts. It's an exposure, not a guarantee.
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Check my deposit for freeThis tool provides general legal information, not legal advice, and does not create an attorney-client relationship. For advice about your situation, consult a licensed Massachusetts attorney.