Massachusetts security deposit law: a flat one-month cap, a separate interest-bearing account, and strict-liability treble damages

The rule

The deposit is capped at one month’s rent — flat, with no furnished-unit or short-lease exception — and must be held in a separate interest-bearing Massachusetts account. M.G.L. c. 186 § 15B(1)(b).

Within 30 days of the tenancy ending the landlord must return the deposit and interest, less any lawful deductions, with a sworn itemized list of damages. M.G.L. c. 186 § 15B.

First month’s rent, last month’s rent and the cost of a new lock may be collected separately, so move-in cash can still total about three months’ rent.

The statement of condition

The landlord must give you a written statement of condition within 10 days of receiving the deposit, and you get 15 days to return it with your own annotations. Skip this paperwork and the landlord loses the right to deduct for damage — a procedural trap that works in the tenant’s favor.

The penalty and where a claim goes

Violations — including failing to hold the deposit in a separate Massachusetts account or failing to return it within 30 days — carry up to treble damages plus 5% interest, court costs and reasonable attorney’s fees. Treble damages are strict liability: no proof that the violation was wilful is required. M.G.L. c. 186 § 15B(6)-(7).

Deposit claims go to the small claims session (limit $7,000) of the District Court or Housing Court; filing fees are tiered by the amount claimed — roughly $40 to $150.

Common questions

How long does a Massachusetts landlord have to return a deposit?

30 days after the tenancy ends, with interest and a sworn itemized list of damages, under M.G.L. c. 186 § 15B.

How much can a Massachusetts landlord charge for a deposit?

One month’s rent — flat, with no furnished-unit or short-lease exception (M.G.L. c. 186 § 15B(1)(b)). First month’s rent, last month’s rent and the cost of a new lock may be collected separately, so move-in cash can still total about three months’ rent.

What if the landlord never put my deposit in an interest-bearing account?

That is one of the violations carrying up to treble damages plus 5% interest, costs and attorney’s fees — and treble damages in Massachusetts are strict liability: you do not have to prove the violation was wilful. M.G.L. c. 186 § 15B(6)-(7).

Is this legal advice?

No. This page is general information about Massachusetts law, with sources. It is not tailored to your situation and we are not a law firm.

Related guides

• How long does a landlord have to return a security deposit?
• How much can a landlord charge for a security deposit?
• New York security deposit law: the 14-day rule and the one-month cap
• Pennsylvania security deposit law: the 30-day rule and the forwarding address that decides your case