Quick answer: At or before the start of a Massachusetts tenancy a landlord may require only the first month’s rent, the last month’s rent, a security deposit of no more than the first month’s rent and the cost of a key and lock. Anything else asked for at that point is more than the statute allows, and the deposit must be held in a separate interest-bearing account.
This Massachusetts security deposit limit calculator applies G.L. c.186, 15B(1)(b). Enter the rent and what the landlord asks for: it shows the most that can be required, each part that is over and the total. It adds up every charge, so an application fee, a pet fee or a move-in fee shows up as an excess.
Massachusetts security deposit rules at a glance
| Rule | What Massachusetts says |
|---|---|
| At the start | First month, last month, a deposit of one month and a key and lock (G.L. c.186, 15B(1)(b)) |
| Security deposit | No more than the first month’s rent (15B(1)(b)(iii)) |
| Last month | Calculated at the same rate as the first month, with a receipt and 5% interest (15B(2)(a)) |
| Later demands | No rent in advance beyond the current month (15B(1)(d)) |
| Late fees | None until 30 days after the rent was due (15B(1)(c)) |
| Where it is held | A separate, interest-bearing Massachusetts bank account, beyond creditors’ claims (15B(3)(a)) |
| Fee in lieu of a deposit | Only as state regulations allow, optional and capped at one month (15B(1)(b)(iii)) |
| Refund | 30 days after the tenancy ends (15B(4)) |
How does the Massachusetts deposit law work?
- The four allowed payments. See the maximum security deposit in Massachusetts.
- Pet deposits and fees. See Massachusetts pet deposits and fees.
- Last month’s rent, receipts and other up-front charges. See up-front charges when renting in Massachusetts.
What does this deposit calculator check?
It multiplies the rent by three for the first month, last month and deposit, adds the key and lock cost you enter and compares the total with what the landlord asked for. A pet deposit, a pet fee, an application fee and a move-in fee are not among the four payments, so the calculator treats any amount you enter there as over the limit. It does not check that the deposit was placed in a bank account, and the return deadline is a separate question, and so are the interest and the penalty: see the Massachusetts security deposit return deadline calculator.
Examples of the Massachusetts up-front limit
| Monthly rent | Asked for | Result | Why |
|---|---|---|---|
| $1,800 | $1,800 + $1,800 + $1,800 | Within the limit | Three months |
| $1,800 | $1,800 + $1,800 + $2,400 | $600 over | The deposit is over one month |
| $1,800 | $1,800 + $1,800 + $1,800 + $300 pet fee | $300 over | A pet fee is not allowed |
| $1,800 | $1,800 + $1,800 + $1,800 + $60 key and lock | Within the limit | The key and lock cost is allowed |
These examples show the arithmetic. They are not statements about a particular lease. A landlord should total every payment before asking for it, and a tenant should keep every receipt.
Related Massachusetts landlord-tenant calculators
These four calculators cover the same tenancy from different angles. From here you can go to the Massachusetts security deposit return deadline calculator for the date the landlord must refund or itemize the deposit, the Massachusetts eviction notice calculator for the notice period before a lease can end and the Massachusetts eviction timeline calculator for the earliest legal dates once an eviction case starts. Each one cites its own Massachusetts statutes and shows only what the law says.
Frequently asked questions
What is the maximum security deposit in Massachusetts?
One month’s rent, equal to the first month’s rent.
What else can a landlord require at the start?
The first month’s rent, the last month’s rent and the cost of a key and lock.
Can a landlord charge a pet deposit or an application fee?
Not as an extra payment at the start: the statute allows only the four payments.
Where must the deposit be held?
In a separate, interest-bearing account in a Massachusetts bank.
Can a landlord charge a late fee right away?
No. None may be charged until 30 days after the rent was due.
Can a lease waive these limits?
No. A conflicting clause or waiver is void.