351 area code — Acton, MA geographic

Data: NANPA public reports, current as of July 28, 2026.

Major area
Acton
Time zone
Eastern
In service since
2001-05-02
Split from
978
Overlay complex
351 / 978
Active prefixes
89
Rate centers
42
Carriers
20

The 351 area code covers Acton, Massachusetts, Eastern time zone, and dates back to May 2, 2001. Together with 978 it forms the 351/978 overlay. Because of number portability and VoIP, the area code tells you where the number was issued, not where the caller is right now.

NANPA lists 89 active NXX prefixes in 351, assigned to 20 carriers. 89 of those prefixes are pooled — shared between carriers in thousands-number blocks. The code spans 42 rate centers (billing localities).

The dialing plan is 10D for home-NPA local calls and 10D across codes.

Use this page to decode where 351 numbers come from — and remember that spoofing means the screen can lie about everything except your own caution.

Its parent code is 978, which it left in 2001.

Largest localities in 351

Largest rate centers in area code 351
Locality (rate center)Active prefixesAlso served by
Acton 6 978
Lowell 5 978
Danvers 4 978
Lawrence 4 508, 978
Georgetown 4 978
Haverhill 4 978
Ashby 3 978
Gloucester 3 508, 978
Merrimac 3 978
Harvard 3 978

FAQ

Where is a 351 number from?

351 is assigned to Acton and surrounding areas of Massachusetts in the Eastern time zone. The three digits after the area code (the prefix) narrow it down to a rate center.

Is 351 a toll-free number?

No. 351 is a geographic code; calls are billed like any other domestic call. Toll-free codes are 800, 833, 844, 855, 866, 877 and 888.

Why do 978 and 351 cover the same place?

They are overlays: when a code runs low on numbers, a new code is added over the same territory instead of splitting it. The 351/978 complex shares one service area, and local calls are dialed with 10 digits.

Why am I getting spam calls from 351 numbers?

Scammers spoof recognizable area codes so calls look local or familiar. A displayed 351 number does not prove the call originated there — see our guide to spotting spoofed calls.