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US area code · Massachusetts

857 area code

Where the 857 area code is, its overlay and how to dial a +1 857 number from anywhere.

CoversBoston, MassachusettsTime zoneEastern (ET)TypeOverlay
Quick answer

The 857 area code is in Boston, Massachusetts, United States (Eastern (ET)). To call from abroad: +1 857 555-0123. It is an overlay, so all 10 digits are dialled.

StateMassachusetts
Main areaBoston
Time zoneEastern (ET)
TypeOverlay
10-digit dialingRequired
In service since03-May-2000

The 857 area code is a geographic North American Numbering Plan (NANP) code covering Boston, Massachusetts. It has been in service since 03-May-2000 and sits in the Eastern (ET) time zone.

Overlay 857 shares its region

Several area codes cover the same geographic area, so two neighbours can have different codes. Because of the overlay, you must dial all 10 digits (area code + number) even for local calls.

857617

How to dial a 857 number

From abroad+1 857 555-0123
Within the US / Canada1 857 555-0123
Locally (same area)857 555-0123

Cities in the 857 area code

A 857 number is usually in one of these places in Massachusetts — 3 counties.

Belmont MiddlesexBrookline NorfolkCambridge MiddlesexChelsea SuffolkEverett MiddlesexMilton NorfolkNewton MiddlesexQuincy NorfolkSomerville MiddlesexSouth BostonWatertown Middlesex

Other Massachusetts area codes

339351413508617774781978

Frequently asked questions

Where is the 857 area code?

The 857 area code is in Boston, Massachusetts, United States (Eastern (ET)).

Is 857 an overlay area code?

Yes. 857 overlays the same region as 617, so callers dial all 10 digits.

Do I have to dial 10 digits for 857?

Yes — dial the area code plus the seven-digit number.

How do I call a 857 number from another country?

Dial your exit code (or +), then 1, then 857, then the number: +1 857 555-0123.

Source: NANPA numbering plan. An area code covers a region, not a precise address — a 857 number does not pinpoint a street or ZIP code.

Number holders in area code 857

Each prefix (the three digits after the area code) is assigned by NANPA to one telephone company. 382 prefixes are in use in 857, shared by 44 companies. The largest holders:

CompanyPrefixesShare
Cellco Partnership Dba Verizon Wireless6718%
Omnipoint Miami E License, LLC6116%
Onvoy, LLC4211%
Metropcs, Inc.257%
Paetec Itel, LLC195%
New Cingular Wireless PCS, LLC185%

Source: NANPA central office code assignments. A number keeps its original prefix when it is ported to another carrier.

Complaints about 857 numbers

Reports to the FTC, last 30 days
397
Recorded messages or robocalls
76%
Rank among area codes
#249 of 670
Most reported subjects
Other (133)
Reducing your debt (credit cards, mortgage, student loans) (100)
Calls pretending to be government, businesses, or family and friends (87)

Period Aug 26 – Sep 24, 2026. These are the numbers shown on the caller ID of the reported calls; many are spoofed and do not belong to the real caller.

Source: US Federal Trade Commission, Do Not Call reported calls data (daily files).

All US area codes United States +1 Map of area code 857 — cities & rate centres

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