857 area code
Area code 857 is in Massachusetts. It covers Boston, Cambridge, Quincy and 27 other places: 80 ZIP codes in Suffolk, Middlesex and Norfolk counties. Local time there is , Eastern Time. In service since 2001 as an overlay: it covers the same area as 617, so a number from there can have either code.
- State
- Massachusetts
- Time zone
- Eastern
- Largest city
- Boston
- Overlays
- 617
- In service since
- 2001
- Rate centres
- 21
- Prefixes assigned
- 362 (3,620,000 numbers)
Who calls from a 857 number
NANPA records the carrier each block of 857 numbers is assigned to. Of the 3.5 million 857 numbers assigned, 50% are with cable, internet-calling, business and other carriers (Onvoy, Bandwidth and PAETEC (Windstream)); 46% with mobile carriers (T-Mobile, Verizon Wireless and AT&T Mobility); 3% with local phone companies.
That is who the numbers were assigned to: people keep their number when they change carrier, so any one number may have moved since.
| Carrier | Kind | Share |
|---|---|---|
| T-Mobile | Mobile | 25% |
| Onvoy | Cable, VoIP, other | 21% |
| Verizon Wireless | Mobile | 16% |
| AT&T Mobility | Mobile | 5% |
| Bandwidth | Cable, VoIP, other | 5% |
| PAETEC (Windstream) | Cable, VoIP, other | 5% |
An area code says where a number was issued, not where the caller is: people keep their numbers when they move, and caller ID can be set to show any number, which the FCC calls spoofing. If a call you did not expect asks for money or personal details, the FCC advises hanging up and calling the company back on a number you look up yourself. Unwanted calls can be reported to the FTC at ReportFraud.ftc.gov.
Places in area code 857
The 17 places with a telephone rate centre of their own using 857, largest first. Each links to its ZIP codes.
| Place | ZIP codes | Population |
|---|---|---|
| Boston, MA | 36 | 666,442 |
| Cambridge, MA | 6 | 118,796 |
| Quincy, MA | 4 | 102,114 |
| Newton, MA | 1 | 89,044 |
| Dorchester, MA | 3 | 86,181 |
| Somerville, MA | 3 | 81,036 |
| Brookline, MA | 2 | 63,266 |
| Everett, MA | 1 | 50,045 |
| Brighton, MA | 1 | 43,149 |
| Chelsea, MA | 1 | 39,908 |
| Hyde Park, MA | 1 | 37,265 |
| Watertown, MA | 3 | 35,543 |
| Milton, MA | 1 | 28,587 |
| Roxbury, MA | 1 | 27,377 |
| Belmont, MA | 1 | 27,175 |
| Charlestown, MA | 1 | 20,032 |
| Winthrop, MA | 1 | 18,759 |
Nearby places using 857
These places have no rate centre of their own in NANPA's records; the nearest one uses 857. Near an area-code boundary that can be wrong for part of a town.
- Dorchester Center
- Jamaica Plain
- Roslindale
- Mattapan
- Chestnut Hill
- Allston
- Roxbury Crossing
- Newtonville
- Brookline Village
- Milton Village
- Nonantum
- North Waltham
- Readville
ZIP codes in area code 857
80 ZIP codes in 30 towns, by the town each is mailed to, largest first. Each links to its own page.
Where 857 numbers are issued
NANPA's rate centres with the most 857 prefixes (each prefix is 10,000 numbers), under NANPA's own abbreviated names.
| Rate centre | Place | Prefixes |
|---|---|---|
BOSTON | Boston | 152 |
CAMBRIDGE | Cambridge | 28 |
BROOKLINE | Brookline | 27 |
ROXBURY | Roxbury | 20 |
NEWTON | Newton | 18 |
QUINCY | Quincy | 14 |
Counties
The counties of its ZIP codes, most residents first, with how many of its ZIP codes each has.
Which code covers where you are now? What area code am I in? answers from your location.
Questions about area code 857
Where is area code 857?
Area code 857 is in Massachusetts. It covers Boston, Cambridge, Quincy and 27 other places: 80 ZIP codes in Suffolk, Middlesex and Norfolk counties.
What ZIP codes are in area code 857?
80 ZIP codes, by the town each is mailed to: Boston (36, 02108 to 02298), Cambridge (6, 02138 to 02238), Quincy (4, 02169 to 02269), Newton (02458) and 26 more towns. The full list is on this page.
What time zone is area code 857 in?
Eastern time.
Is a 857 number a mobile or a landline?
It can be either. 46% of 857 numbers are assigned to mobile carriers and 3% to local phone companies (NANPA, 2026-10-10); the rest are with cable, internet-calling, business and paging carriers. A number keeps its area code when it moves to another carrier.
What area codes overlay 857?
617. They cover the same area as 857, so a new number there can be given any of them.
Does a 857 number mean the caller is in Massachusetts?
Not necessarily. An area code says where the number was first issued. People keep their numbers when they move or switch carriers, and calling software can show any number, so a 857 call can come from anywhere.
Other area codes in Massachusetts
All 9 Massachusetts area codes, by area, with the cities each covers
Source: NANPA NPA database, central office code and thousands-block assignments, 2026-10-10. Places are matched to NANPA's rate centres by name; see sources.
Cite this page
zipcodes.pro. “Area code 857.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/area-code/857
Underlying data is public domain or openly licensed — sources, vintages and licences.