Area Code 857: Massachusetts, Massachusetts
857 is a telephone area code serving Massachusetts. It is part of the North American Numbering Plan and is dialed with the country code +1.
Numbers beginning with 857 are located in Massachusetts, United States (NANP region: Boston).
How to Dial Area Code 857
| Calling from | What to dial |
|---|---|
| Anywhere in the US or Canada | 1 857 XXX-XXXX (10-digit dialing: 857 + 7-digit number) |
| Local call inside the same area code | 7-digit number in most areas; 10 digits where an overlay code is active |
| From the UK or Europe | 00 1 857 XXX XXXX |
| From Australia | 0011 1 857 XXX XXXX |
| From a mobile phone anywhere | +1 857 XXX XXXX |
Whatever country you are calling from, the + symbol replaces the exit code. Save the contact as +1 857 XXXXXXX and it will dial correctly from any phone in the world.
Time Zone for Area Code 857
Calls to a 857 number ring in the America/New_York time zone, standard offset UTC-05:00. Daylight saving time applies here, so the offset moves forward one hour from March to November.
Other Area Codes in Massachusetts
These codes also serve Massachusetts. Area codes are assigned by the North American Numbering Plan Administration (NANPA).
| Area Code | Cities / Coverage |
|---|---|
| 339 | Boston (overlay) |
| 351 | Northeast (overlay) |
| 413 | Springfield |
| 508 | Worcester, Cape Cod |
| 617 | Boston |
| 774 | Central (overlay) |
| 781 | Boston suburbs |
| 978 | Lowell, Lawrence |
See all 9 area codes in Massachusetts →
Frequently Asked Questions
Where is area code 857?
Area code 857 is in Massachusetts, United States. It covers Boston (overlay).
What time zone is area code 857 in?
Area code 857 rings in the America/New_York time zone (UTC-05:00 standard).
Do I need to dial 1 before area code 857?
Yes, for a long-distance call inside the US and Canada you dial 1 first, then 857, then the seven-digit number. The 1 is the North American long-distance trunk prefix — it is not the country code. From outside North America you dial your exit code then 1 then 857.
Is area code 857 toll-free?
No. 857 is a standard geographic area code, so normal long-distance rates apply unless your plan includes them. Toll-free NANP codes are 800, 833, 844, 855, 866, 877 and 888.