Massachusetts Security Deposit Law
A 2026 guide for Massachusetts landlords: how much you can hold, the 30-day deadline to return it, whether interest is required, and the penalties for getting it wrong — plus a free calculator set to Massachusetts's rules.
Deposit cap
1 month's rent
Refund deadline
30 days
Interest required?
Yes
5% annual simple interest (or the rate actually earned in an interest-bearing account) is required.
Separate account?
Yes
Penalty for noncompliance
Noncompliance (no separate account, no receipt, no interest) can result in treble damages plus attorney's fees.
Statute: Mass. Gen. Laws ch. 186, § 15B
Massachusetts security deposit refund calculator
Pre-set to Massachusetts's 30-day deadline and interest rule. Enter the deposit and any deductions to see the refund and the exact due date.
Massachusetts generally requires interest on held deposits. This estimate uses a 5% simple annual rate — confirm the exact current rate for your state before finalizing.
Itemized deductions
Result
$1,500.00
Amount owed back to the tenant
- Deposit held
- $1,500.00
- Estimated interest
- $0.00
- Total deductions
- −$0.00
Legal deadline in Massachusetts
Return the deposit (or an itemized statement of deductions) within 30 days of move-out.
How to return a security deposit in Massachusetts
- 1
Inspect and document the unit
As soon as the tenant moves out, photograph every room and compare it against the move-in condition. In Massachusetts, deductions generally must reflect actual damage beyond normal wear and tear.
- 2
Itemize every deduction in writing
List each deduction with a dollar amount. Massachusetts — like nearly every state — can bar a landlord from keeping any of the deposit if deductions aren't itemized in a written statement.
- 3
Add any interest owed
Massachusetts requires interest on held deposits. 5% annual simple interest (or the rate actually earned in an interest-bearing account) is required. Include the interest in the amount returned.
- 4
Return the balance within 30 days
Send the remaining balance and the itemized statement to the tenant's forwarding address within 30 days of move-out. Missing this deadline is the single most common way landlords lose a deposit dispute.
Massachusetts security deposit FAQ
How much can a landlord charge for a security deposit in Massachusetts?
1 month's rent.
How long does a landlord have to return a security deposit in Massachusetts?
A landlord generally has 30 days after the tenant moves out to return the deposit or send an itemized statement of deductions.
Is interest required on security deposits in Massachusetts?
5% annual simple interest (or the rate actually earned in an interest-bearing account) is required.
Does Massachusetts require the deposit to be held in a separate account?
Yes. In Massachusetts, landlords are generally required to keep security deposits in a separate account rather than commingling them with personal funds.
What happens if a landlord wrongfully withholds a deposit in Massachusetts?
Noncompliance (no separate account, no receipt, no interest) can result in treble damages plus attorney's fees.
Related free tools
Deposit laws in other states
This page summarizes general state-level rules as of 2026 and does not cover city or county ordinances, which can be stricter. Verify against the statute cited above (Mass. Gen. Laws ch. 186, § 15B) or with a local attorney before relying on it.