Security DepositTenant RightsMassachusettsM.G.L. c. 186Landlord-Tenant LawRenters Guide

Security Deposits in Massachusetts: The Complete Rules — and How to Get Yours Back

Massachusetts has some of the strictest security deposit rules in the country. Here's exactly what your landlord must do — and what happens (triple damages) when they don't.

July 17, 2026
8 min read
Boston Property NavigatorEditorial Team

Massachusetts security deposit law (M.G.L. c. 186 §15B) requires a separate interest-bearing account, specific receipts, and a 30-day return deadline. Landlords who don't comply can owe triple damages. Here's the full rulebook, cited to the actual statute.

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BLUF: The Security Deposit Rules

Massachusetts caps a security deposit at one month's rent, requires it to sit in a separate Massachusetts interest-bearing account, and requires specific receipts — miss a step and you can owe the tenant treble (3x) damages plus attorney's fees. This guide walks through every requirement under M.G.L. c. 186 §15B, in the order it actually happens: paying the deposit, holding it, and getting it back.

1️⃣When You Pay: What the Landlord Can Charge and Must Give You

  • Maximum deposit: no more than one month's rent (c. 186 §15B). A landlord may also collect last month's rent in advance and the cost of a new lock and key — but that's it beyond first month's rent.
  • Immediate receipt: at the moment you pay, the landlord must give you a signed receipt with the amount, the date, who received it, and a description of the unit.
  • Statement of condition, within 10 days: a signed list of the unit's condition, including any existing damage or code violations. You have 15 days (or 15 days after move-in, whichever is later) to add or dispute items in writing — if you don't, and the landlord's statement is accurate, you may lose the ability to dispute those items later when the deposit is returned.

2️⃣While It's Held: The Bank Account Rules

Your deposit is your property, held in trust — not the landlord's money to use. The law requires:

  • It must go into a separate, interest-bearing account at a Massachusetts bank, kept apart from the landlord's own funds and beyond the reach of the landlord's creditors (including a foreclosing mortgagee or bankruptcy trustee).
  • Within 30 days, the landlord must give you a written statement naming the bank, its location, the account number, and the amount deposited.
  • Interest: if you live in the unit at least one year, you're entitled to either 5% annual interest or the actual rate the bank paid, whichever is lower, paid out (or credited against rent) on your tenancy anniversary each year.
  • If the property is sold, the new owner has 45 days to tell you in writing that they've received your deposit and where it's held.
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The consequence for skipping this step

If a landlord fails to hold the deposit in a proper Massachusetts interest-bearing account, or fails to send the required 30-day bank notice, they lose the right to keep any part of the deposit — you're entitled to its immediate return, on request, regardless of any damage claim.

3️⃣Getting It Back: The 30-Day Deadline

Within 30 days after your tenancy ends, the landlord must return your deposit, plus any interest owed, minus any lawful deductions. Lawful deductions are narrow: unpaid rent, a real estate tax increase you agreed in the lease to cover, or actual damages beyond normal wear and tear — and for damage deductions, the landlord generally must provide an itemized list, signed under penalty of perjury, describing the damage and the cost to repair it.

If the landlord doesn't return your deposit (or the required itemized list) within 30 days, or deducts for something that isn't a lawful basis, you may be entitled to three times the amount wrongfully withheld, plus interest, court costs, and reasonable attorney's fees.

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Landlord failurePotential consequence

No proper bank account / no 30-day bank notice

Forfeits right to keep any part of the deposit

No receipt at payment, or no statement of condition

May forfeit right to deduct for damage

Deposit not returned within 30 days of move-out

Up to 3x the deposit amount, plus interest, costs, and attorney's fees

Deducted for normal wear and tear or unlisted damage

Tenant can recover the improperly withheld amount, potentially trebled

📝If Your Deposit Isn't Returned

  • Send a written demand letter to your landlord requesting the deposit and any interest owed, and keep a copy.
  • Gather your lease, payment receipt, statement of condition, move-in/move-out photos, and any correspondence.
  • If the landlord doesn't respond or refuses, small claims court is designed for exactly this — see our Small Claims Court guide for the step-by-step process and current filing fees.
  • If the amount is disputed or complex, a demand letter that references M.G.L. c. 186 §15B directly often resolves it before any filing is needed.
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Not legal advice

This is general information about how Massachusetts security deposit law works, not legal advice, and not a guarantee of any outcome. Confirm the current rules with the official sources below or a licensed Massachusetts attorney.

Sources

  1. M.G.L. c. 186, §15B — Security deposits
  2. Mass.gov — Security deposits and last month's rent
  3. Mass.gov — Learn about holding a security deposit
  4. Mass.gov — Learn about paying a security deposit
  5. 940 CMR 3.17 — Attorney General landlord-tenant regulations

Deposit not returned?

Our Small Claims Court guide walks through the exact filing process, fees, and what evidence to bring.

Read the Small Claims guide
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