Boston, Mass., Mun. Code § 9-14 (2026) § 9-14.2

For the purpose of this Section, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
BOOKING AGENT. Any person or entity that facilitates reservations or collects payment for a short-term rental on behalf of or for an operator.
CODE. Boston Zoning Code.
COMMISSIONER. Commissioner of the Inspectional Services Department or a designee.
DND. The City Department of Neighborhood Development
DoIT. The City Department of Innovation and Technology
HOME SHARE UNIT. A residential unit offered as a short-term rental that is the operator’s primary residence. Occupancy shall be limited to five bedrooms or ten guests in a HOME SHARE UNIT , whichever is less.
INELIGIBLE UNITS LIST. A list maintained by the city of residential units deemed ineligible for use as short-term rental units subject to the provisions of Subsection 9-14.4(A).
ISD. The City Inspectional Services Department.
LIMITED SHARE UNIT. A residential unit that is the operator’s primary residence, a portion of which is offered as a short-term rental while the operator is present. Occupancy shall be limited to three bedrooms or six guests in a LIMITED SHARE UNIT , whichever is less. One bedroom must be reserved for the operator.
OPERATOR. A natural person who is the owner of the residential unit that he or she seeks to offer as a short-term rental. Only one owner may be registered as an OPERATOR on the short-term rental registry for a residential unit, and it shall be unlawful for any other person, even if that person is an owner and meets the qualifications of primary resident, to offer a residential unit for short-term residential rental.
OWNER-ADJACENT UNIT. A residential unit offered as a short-term rental that is not the owner’s primary residence but that is located within the same dwelling as the primary residence of, and is owned by, said owner; provided that, OWNER-ADJACENT UNITS used as short-term rentals shall only be allowed in two-family or three-family dwellings where all units are owned by the same unique owner-occupant who serves as the operator; provided further that, for the purposes of owner-occupied three-family residential dwellings, in addition to the unit in which they reside and use as a home share or limited share unit, an operator of an owner-adjacent unit may only register and use one owner-adjacent unit as a short-term rental.
PRIMARY RESIDENCE. The residential unit in which the operator resides for at least nine months out of a 12-month period. PRIMARY RESIDENCE is demonstrated by showing that as of the date of registration of the residential unit on the short-term rental registry, the operator has resided in the residential unit for nine of the past 12 months or that the operator intends to reside in the residential unit for nine of the next 12 months, as demonstrated by at least two of the following: utility bill, voter registration, motor vehicle registration, deed, lease, driver’s license or state-issued identification or proof of residential exemption.
REGISTRATION NUMBER. A unique identification number generated for a single residential unit registered as a short-term rental. REGISTRATION NUMBERS shall be valid for the calendar year during which they are assigned, January 1 through December 31, and shall be associated with both a single residential unit and a single operator. The REGISTRATION NUMBER must be included on any listing or advertisement offering a unit as a short-term rental.
RESIDENTIAL UNIT. A dwelling unit within a dwelling classified as a residential use, as those terms are defined in the Code, but excluding: a congregate living complex; elderly housing; a group residence, limited; a homeless shelter; orphanage; temporary dwelling structure; and transitional housing. The term RESIDENTIAL UNIT shall not include a hotel, motel, executive suite or other non-residential use.
SHORT-TERM RENTAL(S). The use of a residential unit for residential occupancy by a person or persons for a period of fewer than 28 consecutive calendar days for a fee. A SHORT-TERM RENTAL may or may not be facilitated through a booking agent.
SHORT-TERM RENTAL REGISTRY. The database maintained by ISD, in conjunction with DoIT, that includes information on operators who are permitted to offer their residential units as short-term rentals. The SHORT-TERM RENTAL REGISTRY may be a stand-alone registry or may be incorporated into the electronic database maintained by ISD pursuant to Subsection 9-1.3, Inspection and Reinspection of Rental Units; provided that the location of the short-term rental with the SHORT-TERM RENTAL REGISTRY shall be made public.