Massachusetts Security Deposit Law: The 30-Day Deadline, Explained

Thirty days. That’s all the time Massachusetts gives your landlord to return your security deposit — and the state backs that deadline with one of the harshest penalties in the country if they blow it.

The deadline: 30 days, and the clock doesn’t wait

Under Massachusetts General Laws Chapter 186, Section 15B, a landlord has 30 days after your tenancy ends to return your full deposit, or to send you the remaining balance along with an itemized list of deductions. The 30 days starts the day the tenancy actually ends — not whenever the landlord gets around to the walkthrough.

How much they could have taken in the first place

Massachusetts caps the deposit itself at one month’s rent, with no exceptions. If your landlord collected more than that, the excess was illegal from day one. On top of the cap, Massachusetts requires landlords to hold your deposit in a separate, interest-bearing account and pay you interest — either 5 percent per year or whatever the bank actually paid, whichever is lower — within 30 days of each yearly anniversary of your tenancy.

What has to be in the itemized statement

A landlord can’t just hand you a total and call it done. The statement has to list each specific reason for a deduction along with the dollar amount, and Massachusetts is strict about this: if the landlord fails to provide a proper, signed, itemized list within the 30 days, they lose the right to keep any of the deposit for damages, no matter how legitimate the damage actually was.

What happens if they miss the 30 days

This is where Massachusetts law gets serious. If your landlord misses the 30-day deadline, or fails to meet any of the technical requirements — the separate account, the interest, the itemized statement — they don’t just owe you the deposit back. Massachusetts allows you to recover triple damages, plus your attorney’s fees and court costs, on top of the deposit itself. A landlord who ignores this law can end up owing far more than they ever held.

What to do if the deadline has already passed

• Send a written demand citing Massachusetts General Laws Chapter 186, Section 15B and the date your tenancy ended.
• Point out specifically which requirement was missed — no itemized statement, no interest paid, or no separate account — since each one strengthens your claim.
• Ask for the full deposit back, since a missed deadline generally forfeits the landlord’s right to deduct for damages.
• If they still don’t respond, Massachusetts small claims court handles deposit disputes up to $7,000, and you don’t need a lawyer to file.

Not sure exactly how many days have passed, or what your landlord actually owes you? Run the numbers in our free security deposit calculator — it does the date math and flags whether your landlord has already blown the deadline.

For the step-by-step on challenging specific deductions once you do get an itemized statement, see our full deposit dispute guide. And if you’re ready to send a formal demand, our free security deposit dispute letter generator builds it for you in about two minutes.

Quick reference

• Landlord has 30 days after move-out to return the deposit or send an itemized statement.
• Deposit is capped at one month’s rent, held in a separate interest-bearing account.
• Annual interest (5% or the bank rate, whichever is lower) is required.
• Missing the deadline or the technical requirements can mean triple damages plus attorney’s fees.

This article is general information for renters, not legal advice. Landlord-tenant law changes, and city or county ordinances can add rules on top of state law. Confirm specifics with a local tenant rights organization or attorney before acting.