Massachusetts security deposit law: 30 days to return it, and the penalty
How long a landlord has to return a security deposit in Massachusetts, what must be sent, and the penalty, read in Massachusetts General Laws chapter 186, section 15B, as explained by the Massachusetts Housing Court on mass.gov.
The deadline
The landlord must return the deposit and any interest, minus what was rightfully subtracted, within 30 days after you move out. With a written lease, if you move out before it ends, the landlord has up to 30 days after the lease ends.
To keep part of it for damage, the landlord must give you, within the same 30 days, a detailed itemized list of the repair costs, signed, with the written estimates, bills or receipts.
The penalty
If the landlord does not return the balance on time, or does not give the signed list and the documents, the landlord loses the right to keep any part of the deposit.
When the landlord has lost the right to keep the deposit, for example by not returning it on time, the court may award three times the amount of the deposit, plus interest and attorney's fees.
What to do
Send a written demand that cites the law, by certified mail or email, and keep proof. If the landlord does not pay, you can file in small claims court in the county of the rental.
Source: Massachusetts General Laws chapter 186, section 15B, as explained by the Massachusetts Housing Court on mass.gov, read on November 3, 2026.