Published 2026-09-27 · 8 min read

Massachusetts Security Deposit Law 2026: Limits, Deadlines & Deductions

Massachusetts has the strictest security deposit law in the country: the cap is one month's rent, the deposit must sit in a separate, interest-bearing Massachusetts bank account, and it must be returned within 30 days after the tenancy ends. For the failures listed in §15B(6)(a), (d), and (e), §15B(7) awards the tenant three times the deposit or balance owed, plus 5% interest, court costs, and attorney's fees. Everything lives in one statute, Mass. Gen. Laws ch. 186, § 15B, and its receipt, condition-statement, and record-keeping rules are where most cases are won and lost.

The short version: Up front you may collect only first month's rent, last month's rent at the same rate, a security deposit equal to one month's rent, and the key-and-lock purchase and installation cost (§15B(1)(b)). Give a signed receipt when you take the deposit, a statement of condition on receipt of the deposit or within 10 days after the tenancy begins (whichever is later), and a bank receipt naming the bank, amount, and account number within 30 days. Hold the money in a separate interest-bearing Massachusetts bank account; the deposit and prepaid last month's rent both earn 5% per year or the lesser bank amount. Within 30 days after the tenancy ends, return the balance with, for any damage deduction, a list sworn under the pains and penalties of perjury, in precise detail, with written evidence of cost.

Corrections to the earlier version of this page: The old page implied any §15B violation triggers treble damages. It does not: §15B(7) treble damages attach only to §15B(6)(a) (not depositing the funds as §15B(3) requires), (6)(d) (transfer failures), and (6)(e) (failing to return the deposit or balance within 30 days). A missing or late itemized list instead causes forfeiture under §15B(6)(b) — a different sanction. The old page also merged two receipts into one (§15B(2)(b) at receipt; §15B(3)(a) bank receipt within 30 days), and omitted the §15B(2)(a) interest on prepaid last month's rent, the tenant's 15-day condition-statement response, the §15B(5) transfer duties, and the August 1, 2025 fee-in-lieu amendment.

Massachusetts punishes procedural mistakes, not just bad faith: the 30-day deadline, the bank notice, and the sworn itemized statement each have to be right. The Security Deposit Disposition Tracker logs every deduction with its evidence, totals the itemized statement, and timestamps the return against the 30-day clock so a one-day slip never costs you treble damages.

The statute table

Limits: how much can you charge?

No more than one month's rent — the statute sets the deposit equal to the first month's rent, with no exceptions, no pet-deposit add-on, and no two-month deposit for higher-risk tenants (§15B(1)(b)(iii)). The complete upfront list is first month's rent, last month's rent at the same rate, that deposit, and the purchase and installation cost for a key and lock (§15B(1)(b)(i)–(iv)). Any "move-in," "amenity," or "administrative" fee on top conflicts with §15B and is void under §15B(8). One recent change: language added to §15B(1)(b)(iii), effective August 1, 2025, authorizes state regulations for an optional fee in lieu of a deposit, capped at one month's rent and always the tenant's choice — an authorization for future rules, not a right to charge a fee today. Check your numbers with the Security Deposit Max Checker.

The 30-day deadline, precisely

Within **30 days after the termination of occupancy under a tenancy at will, or the end of the tenancy in a valid written lease — balance plus interest, and the sworn list if damage was deducted (§15B(4)).

When the clocks actually start

Massachusetts runs several clocks. The return clock starts at the termination of occupancy or the lease's stated end — not when you inspect or get a forwarding address. The bank-receipt clock runs from receipt of the deposit: the §15B(3)(a) bank receipt is due within 30 days, while the §15B(2)(b) signed receipt is due at receipt itself. The condition-statement clock runs from the later of receipt of the deposit or 10 days after the tenancy commences (§15B(2)(c)). The interest clock starts on the first day of the tenancy for both the deposit and prepaid last month's rent, payable at each anniversary and within 30 days of an early termination (§15B(2)(a), (3)(b)). The transfer clock runs from a transfer of the landlord's interest: the successor's written notice is due within 45 days (§15B(5)).

A worked example

Say rent is $1,800 a month and the deposit is $1,800, at the one-month cap. The tenancy ends on Monday, March 2, 2026, so the 30-day return deadline is Wednesday, April 1, 2026. You find $450 in proper charges — $300 of documented damage beyond wear and tear and $150 of unpaid water charges — and owe a $1,350 balance. By April 1 you must deliver both the $1,350 and, because you deducted for damage, the list sworn under the pains and penalties of perjury, in precise detail, with the bills or estimates behind the $300. If April 1 passes with nothing sent, §15B(6)(e) forfeiture applies and the $450 is lost — and because (6)(e) triggers §15B(7), treble runs on the $1,350 balance. If you never banked the deposit separately, that is a §15B(6)(a) failure and treble runs on the full $1,800.

Deductions and the itemized list

You may deduct only three categories (§15B(4)):

1. Unpaid rent or water charges not validly withheld or deducted under any law (§15B(4)(i));

2. An unpaid increase in real estate taxes the tenant must pay under a tax escalation clause conforming to Mass. Gen. Laws ch. 186, § 15C (§15B(4)(ii)) — a lease sentence about taxes is not enough on its own.

3. A reasonable amount necessary to repair damage caused by the tenant, or anyone under the tenant's control or on the premises with the tenant's consent, reasonable wear and tear excluded (§15B(4)(iii)).

For a damage deduction, the list must be sworn to by the landlord or his agent under the pains and penalties of perjury, itemize in precise detail the nature of the damage and the repairs necessary, and come with written evidence, such as estimates, bills, invoices, or receipts, indicating the actual or estimated cost (§15B(4)(iii)). One trap: no deduction for damage listed in the §15B(2)(c) statement of condition, or in a tenant list you signed, unless you later repaired it and can prove the renewed damage was unrelated and tenant-caused. The statute separately preserves recovery where a tenant wilfully or maliciously destroys property and the cost exceeds the deposit. Generate a compliant letter with the Security Deposit Deduction Letter Generator.

Move-in to move-out compliance checklist

1. Collect only the §15B(1)(b) list. First month, last month at the same rate, a one-month deposit, and the key-and-lock cost — nothing else up front.

2. Give both receipts. The signed §15B(2)(b) receipt when the money changes hands (plus the §15B(2)(a) receipt if you took last month's rent), then the §15B(3)(a) bank receipt within 30 days.

3. Deliver the statement of condition on time. On receipt of the deposit or within 10 days after the tenancy begins, whichever is later, signed, with the statutory notice at the top of page one; calendar the tenant's 15-day response and your 15-day reply (§15B(2)(c)).

4. Bank it separately in Massachusetts. A separate, interest-bearing account in an in-state bank, beyond your creditors' claims (§15B(3)(a)).

5. Keep the §15B(2)(d) record and pay interest annually. Records kept 2 years after the tenancy ends and open to inspection; an interest statement and payment (or deduction notice) at each anniversary, for the deposit and any prepaid last month's rent.

6. On a sale or transfer, hand over the deposit plus accrued interest and ensure the successor sends the written §15B(5) notice within 45 days, with names, business addresses, and telephone numbers.

7. Close out inside 30 days. Return the balance with accrued interest, and for damage send the sworn, precise-detail list with its written evidence in the same window (§15B(4)).

Interest and where the money sits

• Where it sits: a separate, interest-bearing account in a Massachusetts bank, held so the deposit is beyond the landlord's creditors — including a foreclosing mortgagee or trustee in bankruptcy — and transferable to a successor (§15B(3)(a)). It remains the tenant's property and is never commingled (§15B(1)(e)).
• Two receipts, not one: the signed receipt at receipt under §15B(2)(b), and the bank receipt within 30 days under §15B(3)(a) — failure means immediate return.
• Interest required: if held one year or longer, 5% per year or the lesser amount received from the bank, accruing from the first day of the tenancy and payable at each year's end (§15B(3)(b)). Section 15B(3)(b) imposes no tax withholding or reporting duty. Prepaid last month's rent earns the same rate under §15B(2)(a), except for the last month itself, when the advance rent is used.
• The annual statement: at each year's end, send the bank's name and address, the deposit amount, the account number, and the interest payable — and pay the interest or notify the tenant he may deduct it from the next rent (§15B(3)(b)). If 30 days pass with neither, the tenant may deduct it himself. Run your numbers with the Security Deposit Interest Calculator.

The penalty, spelled out

Two sanctions stack:

• Forfeiture (§15B(6)): fail any of the five listed duties — depositing the funds as §15B(3) requires, furnishing the itemized list within 30 days, enforcing a conflicting lease provision or waiver, transferring the deposit under §15B(5), or returning the balance with interest within 30 days — and you forfeit the right to retain any portion of the deposit, and to counterclaim for damage.
• Treble damages (§15B(7)): only three failures — §15B(6)(a), (d), and (e) — carry the multiplier: three times the deposit, or the balance to which the tenant is entitled, plus 5% interest from the date the payment became due, court costs, and reasonable attorney's fees.

Run the worked example through the §15B(7) formula. The $1,350 balance was due on Wednesday, April 1, 2026 and was not returned: treble damages are 3 × $1,350 = $4,050, plus 5% interest running from April 1, 2026, plus court costs and the tenant's reasonable attorney's fees. If the failure was instead never depositing the money separately — a §15B(6)(a) failure, where the whole deposit is owed — the figure is 3 × $1,800 = $5,400, on the same terms. A smaller treble rule covers prepaid last month's rent: fail to pay the §15B(2)(a) interest within 30 days after termination and the award is three times the interest owed, plus costs and fees.

FAQ

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

30 days after the termination of occupancy under a tenancy at will, or the end of the tenancy specified in a valid written lease — the deposit or balance, with any interest due, and the sworn itemized list if anything was deducted for damage (§15B(4)).

What is the maximum security deposit in Massachusetts?

A deposit equal to the first month's rent. Up front you may also collect first and last month's rent and the key-and-lock cost — and nothing else (§15B(1)(b)).

Can I charge a pet deposit on top of the one-month cap?

No. Section 15B(1)(b) fixes the deposit at one month's rent; there is no separate pet-deposit allowance, so a pet charge must fit inside that one-month total.

Does prepaid last month's rent earn interest too?

Yes — §15B(2)(a) requires 5% per year or the lesser bank amount, from the first day of the tenancy, paid annually and in full within 30 days after termination, except that no interest accrues for the last month itself. Failing to pay it within 30 days after termination carries treble damages on the interest, plus costs and fees.

Can I deduct for professional cleaning after move-out?

Only if it goes beyond reasonable wear and tear and amounts to tenant-caused damage under §15B(4)(iii), documented on the sworn list in precise detail with written evidence of cost. Routine turnover cleaning is not a §15B(4) deduction category.

What happens if I miss the 30-day deadline for the itemized list but return the money on time?

You forfeit the right to retain any part of the deposit under §15B(6)(b) — the deductions are lost. On the statute's text, §15B(7) treble damages attach to the §15B(6)(a), (d), and (e) failures, not to (6)(b) standing alone.

What does the tenant's statement-of-condition response actually do?

The tenant has 15 days after receiving the statement (or after moving in, whichever is later) to sign it or return a separate signed list. Damage listed in either, once signed, cannot later be deducted for unless repaired and the renewed damage was unrelated and tenant-caused (§15B(2)(c), (4)(iii)).

What happens to the deposit if I sell the property mid-tenancy?

You must transfer the deposit plus accrued interest to your successor, who is liable from the transfer date and must notify the tenant in writing within 45 days. Failing to transfer or comply is a §15B(6)(d) forfeiture — one of the three failures carrying §15B(7) treble damages (§15B(5)–(7)).

Read the statute yourself

Everything here traces back to Mass. Gen. Laws ch. 186, § 15B. If anything is disputed, the primary sources control:

• Mass. Gen. Laws ch. 186, § 15B (Massachusetts Legislature, official) — the full current text, including the language effective August 1, 2025.
• Mass. Gen. Laws ch. 186, § 15B (Justia) — the same full text on Justia.
• Mass. Gen. Laws ch. 186, § 15B (Cornell LII) — the same text in Cornell's annotated code.

Massachusetts punishes procedural mistakes, not just bad faith: the 30-day deadline, the bank notice, and the sworn itemized statement each have to be right. The Security Deposit Disposition Tracker logs every deduction with its evidence, totals the itemized statement, and timestamps the return against the 30-day clock so a one-day slip never costs you treble damages.

More security deposit guides

• Security deposit laws by state
• Maryland security deposit law
• Michigan security deposit law
• Maine security deposit law
• Minnesota security deposit law

Last verified: October 15, 2026. This is general information, not legal advice. Verify with a licensed Massachusetts attorney before acting.