Massachusetts Security Deposit Law for Landlords: The 2026 Compliance Guide

Massachusetts has the strictest security deposit law in the country. A handful of paperwork slips can convert a routine return into triple damages plus the tenant's attorney's fees — and several of the most common slips happen at move-in, months before the dispute that surfaces them.

This guide walks through every obligation in MGL c.186 §15B — the controlling statute — in the order you'll encounter them: move-in, mid-tenancy, move-out. Every numbered rule links back to the section in the law.

1. Why this law is the biggest source of MA landlord liability

Most landlord-tenant disputes settle for the deposit amount. Security-deposit disputes don't, because §15B includes a fee-shifting provision: when the landlord triggers any of the three §15B(7) clauses, the tenant gets three times the security deposit (or balance to which the tenant is entitled) plus 5% interest from the due date plus court costs plus reasonable attorney's fees (§15B(7)). On a $2,000 deposit fully withheld past day 30, that's $6,000+ in trebled exposure — enough to justify a plaintiff's lawyer taking the case on contingency.

The statute is strict liability for most of its terms. Good intent, a friendly tenant, an honest mistake — none of these are defenses to the deadlines and paperwork requirements.

2. What you can collect at move-in

§15B(1)(b) (as amended effective August 1, 2025) enumerates the only four things you may require a tenant to pay at or before the start of a tenancy:

1. First full month's rent (§15B(1)(b)(i))
2. Last full month's rent, calculated at the same rate as the first month (§15B(1)(b)(ii))
3. A security deposit equal to the first month's rent, but only if it is deposited as required by §15B(3) and the tenant gets the statement of condition required by §15B(2) (§15B(1)(b)(iii))
4. The purchase and installation cost for a key and lock (§15B(1)(b)(iv))

The 2025 amendment also authorizes the Executive Office of Housing and Livable Communities to permit a fee in lieu of a security deposit with detailed guardrails (must be optional, capped at one month's rent total, must be offered to every approved applicant regardless of protected class) — see §15B(1)(b)(iii)(A)–(F). The implementing regulations are the binding text here; this provision is new and worth checking the regulatory updates before you offer the option.

You also cannot demand more rent in advance or a larger deposit after the tenancy has started (§15B(1)(d)). Once the door closes, you're stuck with what you collected at signing.

3. The bank-receipt requirement and its 30-day clock

The single most-litigated paragraph in §15B is §15B(3)(a). It does two things:

1. The deposit must go into a separate, interest-bearing account in a bank located within the Commonwealth, on terms that place the deposit beyond the reach of the landlord's creditors (including a foreclosing mortgagee or bankruptcy trustee).
2. Within 30 days of receiving the deposit, you must give the tenant a receipt stating:
   • the name of the bank
   • the location of the bank
   • the amount of the deposit
   • the account number

Miss any of those four fields, or miss the 30-day clock, and the statute itself says the tenant is entitled to immediate return of the security deposit (§15B(3)(a), final sentence).

Practical implications:

• A general operating account at a national bank with a Massachusetts branch isn't compliant if the deposit is commingled with other funds. The account must be separate, not just MA-located.
• "Interest-bearing" means the account itself must earn interest. A no-interest business checking account fails the test even if you pay the tenant 5% out-of-pocket each year.
• Online-only banks: confirm they are chartered or branched in Massachusetts before relying on them.

4. The 10-day statement of condition

§15B(2)(c) requires a separate written statement of the present condition of the premises, given to the tenant either:

• upon receipt of the security deposit, or
• within 10 days after commencement of the tenancy, whichever is later.

The statement must include a comprehensive listing of any existing damage, including any state sanitary or building code violations certified by a local board of health or building official, or adjudicated by a court.

The statute specifies a verbatim notice that must appear at the top of the first page, in twelve-point bold-face type:

This is a statement of the condition of the premises you have leased or rented. You should read it carefully in order to see if it is correct. If it is correct you must sign it. This will show that you agree that the list is correct and complete. If it is not correct, you must attach a separate signed list of any damage which you believe exists in the premises. This statement must be returned to the lessor or his agent within fifteen days after you receive this list or within fifteen days after you move in, whichever is later. If you do not return this list, within the specified time period, a court may later view your failure to return the list as your agreement that the list is complete and correct in any suit which you may bring to recover the security deposit.

The tenant then has 15 days to either sign or submit a separate list of damages. If the tenant submits a list, you have 15 days from receiving it to return a copy with either your signed agreement or a clear statement of disagreement (§15B(2)(c)).

Why this matters at move-out: you cannot deduct from the deposit for any damage that was on the move-in condition statement (or on the tenant's separate list that you signed) — unless you repaired it during the tenancy and can prove the renewed damage is unrelated and tenant-caused (§15B(4)).

A missing or noncompliant condition statement isn't on the §15B(6) forfeiture list, but it cripples you at move-out as a practical matter: under §15B(4), you cannot deduct for any damage that was already itemized on a statement signed by the tenant, and without a proper move-in statement you have no documented baseline to prove the condition changed during the tenancy. The result is the same — deductions become very hard to defend — even though the condition-statement failure is not itself a statutory forfeiture ground.

5. Annual interest payment mechanics

§15B(3)(b): if you hold a deposit for one year or longer from the start of the tenancy, you owe interest from day one.

The rate is 5% per year, or the lesser amount actually received from the bank where the deposit has been held. If your bank pays 0.05%, you owe the tenant 0.05% — not 5%. The bank's rate caps your obligation.

At the end of each year of tenancy, you must give or send the tenant a statement containing:

• bank name and address
• amount of the deposit
• account number
• interest payable

Along with the statement, you must either pay the interest or include a notice that the tenant may deduct the interest from their next rent payment. If 30 days pass after the tenancy-year anniversary without payment or notice, the tenant may unilaterally deduct the interest from the next rent payment (§15B(3)(b)).

Interest is also due within 30 days of termination if the tenancy ends mid-year (§15B(3)(b)).

6. The 30-day return clock and itemized deductions

§15B(4): within 30 days after termination of occupancy (tenancy-at-will) or end of tenancy (lease term), return the deposit or any balance to the tenant. The statute permits exactly three categories of deduction:

1. Unpaid rent or water charges that were not validly withheld or deducted under any general or special law (§15B(4)(i))
2. Unpaid increases in real estate taxes the tenant is obligated to pay under a tax escalation clause conforming to MGL c.186 §15C (§15B(4)(ii))
3. A reasonable amount necessary to repair damage caused by the tenant or someone on the premises with the tenant's consent — reasonable wear and tear excluded (§15B(4)(iii))

For any damage deduction, you must provide within those 30 days:

• An itemized list of damages, sworn to under pains and penalties of perjury, describing each damage in precise detail and the repairs necessary, and
• Written evidence — estimates, bills, invoices, or receipts — of the actual or estimated cost.

No deduction is permitted for any damage that was listed on the move-in condition statement (or the tenant's countersigned separate list), unless you repaired it during the tenancy and can prove the renewed damage is unrelated.

Reasonable wear and tear is the most-disputed line on the deduction itemization. The statute doesn't define it; case law treats it as the deterioration that occurs from ordinary, careful use — faded paint, minor carpet wear, small nail holes from pictures. Anything you deduct under "damage" should be defensible as exceeding ordinary use.

7. Which violations actually trigger triple damages

This is the part most landlords get wrong. §15B(6) lists five forfeiture grounds — any one means you lose the right to keep any of the deposit and to counterclaim for damages:

§15B(7) names only clauses (a), (d), and (e) as the treble-damages triggers. The remedy is "three times the amount of such security deposit or balance thereof to which the tenant is entitled plus interest at the rate of five per cent from the date when such payment became due, together with court costs and reasonable attorney's fees."

The other two forfeiture grounds — itemized-list failure and conflicting-lease-provision — cost you the deposit but not the multiplier. Still painful, just not catastrophic.

8. Edge cases: no SSN, mid-tenancy sale, foreclosure

Tenant without an SSN. Banks may require alternate documentation (passport, ITIN). The statute does not exempt landlords from the separate-account requirement based on tenant identification. MassLegalHelp guidance is that a missing SSN does not preclude statutory compliance — work with a bank that accepts alternatives.

Sale of the property mid-tenancy. §15B(5) requires you to transfer the deposit (plus accrued interest) to your successor in interest. The successor must notify the tenant within 45 days of the transfer, with the new owner's name, business address, and telephone number, and the agent's same info if applicable.

If you don't transfer the deposit, a successor in interest generally assumes liability to the tenant — but §15B(5) carves out exceptions, including a city or town that takes title under c.60 and a foreclosing mortgagee (or mortgagee in possession) that is a state- or federally-chartered financial institution. Regardless of the successor's status, your failure to transfer is itself a §15B(6)(d) violation — triple damages under §15B(7).

Foreclosure or bankruptcy. §15B(1)(e) and §15B(3)(a) both reinforce that the deposit "shall not be subject to the claims of any creditor of the lessor or of the lessor's successor in interest, including a foreclosing mortgagee or trustee in bankruptcy." This protection is structural — if you commingle deposits with operating funds, you lose this protection in practice even though the statute creates it on paper.

9. The five most common compliance traps

Patterns we see repeatedly in disputes that escalate:

1. The "we trust each other" account. Landlord deposits into their regular business checking instead of a separate account. Triple damages under §15B(6)(a) → §15B(7), full stop.
2. The forgotten 30-day receipt. Account is correct, but the bank-name-account-number receipt is never given (or is sent more than 30 days after deposit). Tenant entitled to immediate return per the last sentence of §15B(3)(a).
3. The verbal condition statement. "We walked through together at move-in and agreed it was fine" doesn't satisfy §15B(2)(c). The statement must be written, with the boldface notice, signed.
4. The day-31 return. Landlord ties up loose ends with contractors and mails the check on day 33. Triple damages under §15B(6)(e) → §15B(7). The 30-day clock is a hard deadline, not a goal.
5. The "deducted from deposit" repair quote without backup. Landlord sends a one-line "kept $400 for cleaning" with no itemized list and no receipts. Forfeiture under §15B(6)(b). Deposit returns in full even if the cleaning was legitimately needed.

The pattern across all five is the same: the statute is procedural. Doing the right thing in spirit isn't enough — the document trail has to exist when a court asks for it.

10. Tools — calculate the interest you owe

The deposit-interest math under §15B(3)(b) is the part landlords most often guess at. We built a free calculator so you don't have to: enter the deposit amount, the lease start date, and (optionally) your bank's actual interest rate, and it returns the statutory interest owed to date.

11. How Tenvale helps

Tenvale is built for the way Massachusetts landlords actually work. Deposits, escrow bank, annual interest, and condition-statement records live in one place, with the 30-day clocks visible on the dashboard so they don't slip.

Full statutory-deadline automation — automatic 30-day-receipt generation, annual interest statements, move-out itemization workflow — is on the product roadmap. Today, the foundation is in place; the workflow polish ships continuously.