What area code is 857?
Here's everything about it.
Instant lookup for the 857 area code — location, time zone, cities served, and who's been calling from it. No sign-up, no app.
857 at a glance
Summary
Cities & regions served by 857
Boston (overlay)Showing 12 of 16 recorded communities — major cities first.
Where 857 sits on the map
Overlay of 617Coverage area
About the 857 region
857 covers Boston in Massachusetts, including Essex, Middlesex, Norfolk, Suffolk and Belmont. The code has been in service since 2001.
857 itself is an overlay: it shares its territory with 617 and was introduced when those codes ran low on new number combinations. New lines may receive either code, calls between them are local, and 10-digit dialing is required across the region.
Overlaid on 617.
Who called me from 857?
Community reports- Caller ID is trivially spoofed: an incoming call that displays 857 does not prove the caller is really in the 857 region or even in the United States.
- Avoid calling back unknown one-ring numbers — some premium-rate scams rely on curiosity callbacks.
- Never share verification codes, payment details, or remote access during an unsolicited call, even if the caller claims to be your bank or a government agency.
- When a 857 call pressures you to act immediately, hang up and contact the organization directly through its official number.
Be the first to add a community report for a 857 number below.
Frequently asked questions
FAQWhat area code is 857?+–
857 is a telephone area code serving Boston in Massachusetts, United States, in service since 2001.
Where is area code 857 located?+–
It covers Essex County, Middlesex County, Norfolk County and other counties, including Essex, Middlesex, Norfolk, Suffolk and Belmont in Massachusetts.
What cities are in area code 857?+–
Major communities on record include Essex, Middlesex, Norfolk, Suffolk and Belmont, among others. The code's territory spans the Boston region of Massachusetts.
What time zone is 857?+–
857 observes Eastern (ET), which is UTC−5 / −4 DST and follows daylight saving time.
When did area code 857 start?+–
857 entered service in 2001. Its history: overlaid on 617.
Why does area code 857 exist?+–
857 is an overlay of 617: it covers the exact same territory and was introduced when the original code ran low on new number combinations. New lines may receive either code, calls between them are local, and 10-digit dialing applies.
Is 857 a scam area code?+–
Scam and robocall traffic can use any North American code, 857 included — caller ID is easy to spoof, so the code alone does not tell you who is really calling. Check the community reports on this page before calling back an unknown 857 number, and report anything suspicious.
Can I get a 857 phone number?+–
Yes — most mobile carriers and VoIP providers let you request a 857 number regardless of where you physically live, although in an overlaid region you may be assigned 617 instead.