Massachusetts Security Deposit Law (c. 186 §15B), Explained
Massachusetts has one of the strictest security-deposit statutes in the nation. For tenants, it's a source of real leverage — sometimes worth more than the rent in dispute. For landlords, it's a minefield where a single paperwork slip can mean triple damages plus attorney's fees. Here's how G.L. c. 186 §15B works.
How much can a landlord hold?
A security deposit in Massachusetts generally cannot exceed one month's rent. At the start of a tenancy, the most a landlord may collect is typically first month's rent, last month's rent, a security deposit (up to one month), and the cost of a new lock and key. Charging more than that, or demanding extra fees on top, runs into §15B.
Where the money must be kept
A security deposit isn't the landlord's money to spend. It must be held in a separate, interest-bearing account in a Massachusetts bank, kept apart from the landlord's own funds. The tenant is entitled to information identifying the account, and to interest on the deposit (generally paid annually). Commingling the deposit with personal funds — or failing to account for interest — is a violation.
Required receipts and the statement of condition
The statute requires specific paperwork, on specific timelines:
- A receipt for the deposit, identifying the amount, the bank, and the account.
- A statement of condition describing the condition of the unit, given to the tenant within a set period after the deposit is received or the tenant moves in. The tenant has a window to respond and note disagreements.
- Annual interest payments or credits, with documentation.
These requirements are technical, and courts apply them strictly. Missing or late paperwork is one of the most common — and costly — landlord mistakes.
The 30-day return deadline
When the tenancy ends, the landlord generally must return the deposit — with interest — within 30 days. Lawful deductions are limited (for example, unpaid rent or actual damage beyond reasonable wear and tear) and must be supported by an itemized list of damages with estimated or actual repair costs, sworn to under the penalties of perjury, plus supporting documentation. Vague or undocumented deductions don't hold up.
When violations trigger triple damages
This is what gives §15B its teeth. Certain violations entitle the tenant to triple (treble) the deposit amount, plus interest, court costs, and reasonable attorney's fees. The violations that can carry triple damages include:
- Failing to return the deposit (or the proper balance) within 30 days after the tenancy ends;
- Failing to hold the deposit in a separate, interest-bearing account, or otherwise not accounting for it;
- Failing to provide the required itemized, sworn list of damages when withholding part of the deposit.
In practice, this means a deposit of, say, $1,500 can become a $4,500 exposure — before fees. That's often larger than the back rent at the center of an eviction.
Why this matters in an eviction
In a summary-process case, a tenant can raise a deposit violation as a counterclaim. Because the penalties can be three times the deposit plus attorney's fees, a deposit claim frequently changes the math of the whole case — turning a straightforward nonpayment eviction into a negotiation, or even a net recovery for the tenant. See how the numbers interact in our free exposure calculator, or read the broader tenant guide to answering a Notice to Quit and the landlord summary-process timeline.
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