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US area code · Massachusetts

Area code 857

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.

Missed a call from +1 857?

In the 30 days to September 24, 2026, 397 unwanted calls showing a 857 number were reported to the US Federal Trade Commission, 76% of them recorded messages or robocalls. That puts 857 at #249 of 670 area codes reported.

Other133
Reducing your debt (credit cards, mortgage, student loans)100
Calls pretending to be government, businesses, or family and friends87
Dropped call or no message33
Before you call back
  • If you do not know anyone in Massachusetts, do not call back: a genuine caller will leave a message or send a text.
  • Scammers fake the number shown on caller ID, so a 857 number can hide a caller anywhere in the world.
  • Never give a code received by text or a bank detail to an unknown caller. In the US, calls can be reported at reportfraud.ftc.gov.

Who issues +1 857 numbers

Phone companies hold blocks of numbers in each area code. The main holders in 857:

Cellco Partnership Dba Verizon Wireless 67Omnipoint Miami E License, LLC 61Onvoy, LLC 42Metropcs, Inc. 25Paetec Itel, LLC 19New Cingular Wireless PCS, LLC 18

About 22.5% of the 382 prefixes in use belong to mobile carriers: a 857 number is often a cell phone, and it may have moved to another carrier since.

Sources: FTC Do Not Call reported calls (numbers as reported by consumers, not verified), NANPA central office code assignments.

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