Lease renewals and rent increases

Lease or tenancy at will

Most rentals in Greater Boston run on a written lease for a fixed term, often twelve months. During that term the rent and the terms in the lease stay as written. The owner cannot raise the rent mid-lease unless the lease itself allows it, and the tenant cannot shorten the term on their own. A change at the end of the term is made with a renewal agreement or a new lease.

A tenancy at will has no end date. Under c.186 §12, either side ends it with written notice. When rent is paid monthly, the notice must equal the interval between rent days or 30 days, whichever is longer, and the end date must fall at the end of a rental period. The law lets that written notice include an offer to create a new tenancy on different terms, which is how an owner raises the rent under a tenancy at will.

Check your lease for what happens if the end date passes and nothing new has been signed. Leases handle a tenant who stays on in different ways, and the answer decides how much notice either side needs.

When to start the conversation

A large share of Boston leases start on September 1, and tenants looking for a September move start around March or April. For a lease ending August 31, raise the renewal in late winter. If the tenant is leaving, you then have the whole spring season to show the unit.

In practice, renewals in this market are usually settled about two months before the next start date. A unit that is not renewing is listed by then. After that window, fewer renters are looking and there is less time to show the unit.

If a lease currently ends in a slow month, use the renewal to move the end date. Ending on June 30 or August 31 puts the next turnover in the busiest part of the year. Where most leases start September 1, fall is usually a slower time to find a tenant.

Setting the renewal rent

The renewal rent follows the market at the time of renewal, not the market when the lease was signed. Look at what comparable units are renting for that season, not what they are listed for.

Then add up what a turnover costs. One vacant month is about 8.3% of a year’s rent. Since August 1, 2025, a broker hired by the owner is paid by the owner, so finding a new tenant through a broker adds a fee of its own. Cleaning, small repairs and a few weeks of showings come on top. If the market has moved less than those costs, keeping a reliable tenant at a modest increase usually leaves the owner ahead.

A two-year term gives both sides stability and saves one round of relisting. The trade-off is that the owner gives up adjusting the rent next year.

Putting the renewal in writing

Send the offer in writing with the new rent, the new term and the date you need an answer. Once agreed, sign a renewal agreement or a new lease that restates the rent, the dates, who pays each utility and any changed rules.

The deposit and last month’s rent already held stay in place, and so do the duties that come with them: the separate bank account for the deposit, interest at the end of each year of the tenancy, and the annual statements.

If you decide not to renew, tell the tenant in writing well ahead of the end date. If a tenant does not leave when the tenancy ends, only a court can order them out; the process is outlined in the first-rental guide.

Retaliation and equal treatment

Under c.186 §18, if a tenant has taken a protected step, including reporting a code violation to a board of health or other authority, complaining about a violation in writing to the owner or the owner’s agent, taking legal action or joining a tenants’ union, then a rent increase, a notice ending the tenancy (other than for nonpayment) or a substantial change in terms within the next six months is presumed to be a reprisal. The owner can overcome that presumption only with clear and convincing evidence of an independent reason, and of having taken the same step at the same time anyway.

If a renewal follows a repair dispute, write down the market basis for the new rent before you send it. Apply the same renewal standards to every tenant; fair housing law covers renewals as well as first leases.