857 Area CodeBoston, MA
Area code 857 covers Boston and nearby communities in Massachusetts, in the Eastern Time (ET) zone, home to about 1.3 million people across 12 cities. It overlays 617, so the same region uses both and every local call needs all ten digits.
Where is area code 857?
Area code 857 serves part of Boston, MA and the surrounding areas. It has a single overlay (617) that serves the same area.
Overview of the 857 Area Code
What is the 857 area code?
The 857 area code serves Boston, Massachusetts, alongside other established area codes. When you see a 857 number, it indicates a local number within this geographic area.
Why was area code 857 created?
The 857 area code was introduced as an overlay to add numbers in Boston once the existing area code 617 began to run out of available prefixes. It added a new supply of numbers without requiring current residents to change their existing digits.
Geographic Coverage of the 857 Area Code
The 857 area code serves Boston and surrounding areas in Massachusetts. It operates within the Eastern Time (ET) time zone. It complements the coverage of area code 617. This area code covers several key cities, including:
- Boston
- Cambridge
- Quincy
- Newton
- Somerville
- Brookline
Got a call from an 857 number? It came from Boston, MA. Since 857 overlays with 617, every local call in the region needs all ten digits to land on the right line. Inside 857, Boston holds about 51% of the population; the rest is split across 11 smaller cities.
Boston Area Codes Overview
Boston is served by multiple area codes, reflecting its telecommunications needs. The 857 area code operates alongside 617. Here are the area codes serving this region:
The introduction of the 857 area code helped prevent number exhaustion, ensuring a continuous supply of phone numbers across the geographic area.
What cities does area code 857 cover?
| City | State | Population | % of Area Code | % of City |
|---|---|---|---|---|
| Boston | MA | 673,458 | 37% | 65% |
| Cambridge | MA | 121,186 | 4% | 100% |
| Quincy | MA | 103,434 | 17% | 100% |
| Newton | MA | 90,700 | 11% | 100% |
| Somerville | MA | 82,149 | 3% | 99% |
| Brookline | MA | 58,732 | 4% | 100% |
| Everett | MA | 51,825 | 2% | 99% |
| Chelsea | MA | 40,245 | 2% | 100% |
| Watertown Town | MA | 31,915 | 3% | 100% |
| Milton | MA | 27,003 | 8% | 100% |
* Sources: Population – U.S. Census Bureau PEP, Vintage 2024 (SUB-IP-EST2024-POP). Area code assignments – NANPA CO Code data. See our data methodology.
Has area code 857 been reported for unwanted calls?
Yes – 499 unwanted-call complaints were reported to the FTC for numbers showing a 857 area code (May 29 – Jul 2, 2026).
- 72% robocalls
- ↑ 16% vs prior period
Most-reported subjects
- Other37%184
- Reducing your debt (credit cards, mortgage, student loans)31%154
- Calls pretending to be government, businesses, or family and friends16%81
* Caller ID is easily spoofed, so these figures reflect the number shown on caller ID, not the caller's true location – an area code alone never identifies a caller. The FTC does not verify the facts in these complaints. Source: FTC Do Not Call (DNC) Reported Calls Data, retrieved 2026-07-05.
Which prefixes and exchanges belong to area code 857?
34% assigned to a telco
- 71% Landline
- 29% Wireless
- 0% Unknown
| Prefix | Usage | Carrier |
|---|---|---|
| (857)200- | Wireless | Verizon Wireless |
| (857)201- | Wireless | Sprint Spectrum |
| (857)202- | Wireless | Verizon Wireless |
| (857)203- | Landline | Verizon New England |
| (857)204- | Landline | Omnipoint Miami E License |
| (857)205- | Wireless | New Cingular Wireless Pcs |
| (857)206- | Wireless | Verizon Wireless |
| (857)207- | Wireless | Verizon Wireless |
| (857)208- | Wireless | Verizon Wireless |
| (857)209- | Landline | Level 3 Communications |
Frequently Asked Questions about the 857 Area Code
Who called me from a 857 number?
A 857 number is assigned to Boston, Massachusetts, so a call may come from there. But caller ID is easy to fake, and scammers often spoof a local 857 code to look nearby, so a 857 number doesn't prove the caller is local. Recently, 499 unwanted-call complaints were reported to the FTC for numbers showing the 857 code (72% flagged as robocalls). If you don't recognize the number, let it go to voicemail; a real caller will leave a message.
Is 857 a scam area code?
No area code is a scam on its own. 857 is a normal, officially assigned code for Boston, Massachusetts. Spam callers spoof local codes to raise the odds you answer, so 857 on your caller ID says nothing about who is really calling. Recently, 499 unwanted-call complaints were reported to the FTC for numbers showing the 857 code (72% flagged as robocalls). Judge the call itself, not the area code.
Why do I keep getting calls from the 857 area code?
Repeated calls from different 857 numbers are usually spoofing: a robocaller rotates through 857 numbers so each call looks local and slips past simple blocks. Recently, 499 unwanted-call complaints were reported to the FTC for numbers showing the 857 code (72% flagged as robocalls). Blocking one number rarely helps; voicemail screening, your carrier spam filter, and the Do Not Call Registry work better.
Should I answer an unknown 857 number?
If you aren't expecting a 857 call, let it ring to voicemail. Legitimate callers leave a message, most robocallers hang up when no one picks up, and answering can mark your number as active and bring more calls.
How do I block calls from the 857 area code?
Block a single 857 number from your recent-calls list (iPhone: tap the number, then Block this Caller; Android: tap the number, then Block or report spam). To cut the volume, turn on Silence Unknown Callers on iPhone or spam protection on Android, enable spam filtering from your carrier, and register at DoNotCall.gov. Blocking the entire 857 code also stops legitimate local calls, so use it only as a last resort.
Where is area code 857?
Area code 857 covers Boston and the surrounding area in Massachusetts, spanning 12 cities with about 1,324,115 residents. It shares its area with overlay code 617.
Is 857 a real area code?
Yes. 857 is an active code in the North American Numbering Plan, assigned by NANPA and in service for Boston, Massachusetts. A real code can still show up on spoofed spam calls, so treat unknown 857 calls with normal caution.
What timezone is the 857 area code in?
The 857 area code is in the Eastern Time (ET). Because a number can be kept when someone moves or switches to VoIP, a specific 857 caller may not be in that zone.
How do I call a 857 number from abroad?
From outside the US, dial your country's exit code, then 1 (the US country code), then 857 and the seven-digit number. From a mobile phone you can usually just enter +1 857 followed by the number and let the phone add the exit code for you.