What’s the maximum security deposit a landlord can charge in Massachusetts?

The only four charges allowed at move-in

Most states cap the security deposit and leave the rest to the market. Massachusetts goes further: it lists everything a landlord may collect at the start of a tenancy, and the list has exactly four items.

The four-item list is the whole game. When a Massachusetts lease bill includes a line that isn’t one of those four, it isn’t a gray area or a negotiation opener — it’s a charge the legislature specifically decided landlords don’t get to make. Here’s what it tends to look like on paper:

The first three lines are legal. The move-in fee and the pet deposit are not, and neither would be an “application fee” collected before this stage. One honest wrinkle: a genuine lock-and-key cost is allowed — so a $40 key line item is fine, while a padded “key fob deposit” far beyond the cost of the hardware isn’t. (Broker fees are their own story with their own 2025 law — see our guide to Massachusetts broker fees.)

The deposit comes with strings attached — for the landlord

Taking a security deposit in Massachusetts signs the landlord up for a set of obligations that many — especially smaller landlords — never follow. Each one is a right you hold from day one:

• A separate, protected bank account. Your deposit must be held in an interest-bearing account in a Massachusetts bank, walled off from the landlord’s own money and their creditors. It’s your money in trust, not their working capital.
• A receipt naming the bank. Within 30 days of paying, you’re entitled to a receipt with the bank’s name, address, and the account number.
• A statement of condition. A landlord who takes a deposit must give you a written statement of the unit’s current condition within 10 days of move-in. Sign it only after correcting it — it’s the baseline your deposit will be judged against when you leave.
• Annual interest. 5% per year, or the actual rate the bank pays, owed to you each year of the tenancy. The same rule covers last month’s rent paid in advance.

These aren’t technicalities. Holding the deposit improperly is itself a violation that can trigger the triple-damages provision below — which is why a renter who knows this list walks into a deposit dispute with far more leverage than the dollar amount suggests.

What can come out of your deposit when you leave

Only three categories of deductions are lawful:

1. Unpaid rent (that you didn’t lawfully withhold),
2. Your agreed share of a real-estate tax increase, if your lease has a valid escalator clause, and
3. The reasonable cost of repairing damage you caused, beyond reasonable wear and tear.

For damage deductions, the landlord owes you a sworn, itemized statement of the damage with supporting evidence within 30 days after the tenancy ends. “Cleaning” a unit back to better-than-you-found-it, repainting after years of normal living, or vague “restoration fees” with no itemization are the classic overreaches — normal wear and tear is the landlord’s cost, by law.

The 30-day deadline and the triple-damages rule

The deposit, plus any interest owed and minus any lawful deductions, must be back in your hands within 30 days after the tenancy ends. Miss that window — or hold the deposit in the wrong kind of account, skip the interest, or rely on an automatic forfeiture clause — and § 15B exposes the landlord to three times the amount wrongfully withheld, plus interest, court costs, and reasonable attorney’s fees.

That multiplier changes the negotiation. A landlord sitting on a $2,400 deposit with a weak itemization isn’t risking $2,400 — they’re risking north of $7,000 plus your lawyer’s bill. You don’t have to threaten anyone with it; you just have to show you know it. A calm letter that cites the statute, states the date the tenancy ended, and asks for the deposit and interest by a specific date resolves a remarkable share of these disputes on its own.

And watch for this clause, which is a violation just by existing in the lease:

If your lease asks for more than the law allows

Before signing: treat an illegal fee as information. Sometimes it’s a landlord who doesn’t know the law; sometimes it’s one who’s counting on you not knowing it. Either way, you can decline the specific line without torching the deal: “Section 15B limits move-in charges to first, last, security, and lock — I’m ready to sign with those four.” You’ll learn a lot about your future landlord from what happens next.

After signing: nothing about a signature makes an illegal charge collectible. Demand letters citing § 15B, the Attorney General’s consumer complaint process, and small claims court (up to $7,000, designed to be used without a lawyer) are all built for renters — and the treble-damages provision means it’s usually the landlord, not you, who should want to settle quickly.