Area code 351 – Massachusetts
351 has served Massachusetts since 2001, split from 978. It is still largely empty: 91 of 786 number blocks allocated. No carrier dominates: Other CLEC / VoIP 30.8%, Onvoy / Inteliquent 30.8%, T-Mobile 11.0%. It shares its geography with overlay codes 978, so local calls take all ten digits. Spam complaints are comparatively rare: 222 in the 33 days to 30 October 2026, 330th of the 422 codes with five or more complaints.
- State
- Massachusetts
- In service since
- 2001
- Time zone
- Eastern
- Shares area with
- 978
Who holds 351 number blocks
Share of the 91 assigned NXX blocks (11.6% of the 786 possible), across 22 carriers. This is share of number blocks, not of subscribers.
- Onvoy30.8%
- Other CLEC / VoIP27.5%
- T-Mobile14.3%
- Charter5.5%
- Verizon5.5%
- AT&T5.5%
- Peerless3.3%
- Bandwidth3.3%
- Comcast2.2%
- Vonage1.1%
- Dish1.1%
Spam complaints naming 351
FTC Do Not Call complaints where the caller ID was a 351 number, 28 Sep – 30 Oct 2026 (33 days). Caller IDs on spam calls are frequently spoofed, so these are complaints about the code, not calls proven to originate in it.
Rate centers in 351
NANPA allocates number blocks to rate centers and records their names abbreviated to ten characters, so these are NANPA's codes rather than place names – CHAMPAURBN is Champaign-Urbana, NWYRCYZN01 is a New York City zone. We show them unchanged instead of guessing at the full names. Showing the largest 5 of 44.
Timeline
- 2001 351 goes into service, split from or overlaid on 978.
More about 351
Separate pages for the questions that need their own answer: what time it is there, what the complaint data says, who holds the number blocks, and how the code compares with the one it shares its area with.
Frequently asked about 351
What state is area code 351?
Massachusetts. It covers the same area as 351/978.
Is a call from 351 a scam?
Not by itself. 351 drew 222 FTC complaints in the 33 days to 30 October 2026, 330th of 422 ranked codes – mid-pack or lower. Spam callers spoof caller IDs, so the only useful check is the full number.
Which carrier owns 351 numbers?
Other CLEC / VoIP holds the largest share of assigned number blocks at 30.8%. The rest is spread across 3 other carriers. This is share of number blocks, not of subscribers – people keep their numbers when they switch carriers.
Do I need to dial 10 digits in 351?
Yes – ten digits for local calls in 351, because it shares its area with another code.
Sources and verification
- NANPA – NPA Database (npa_report.csv), file date 11/01/2026, retrieved Nov 1, 2026
- NANPA – CO Code Assignment Records, All States (utilized), file updated 11/01/2026, retrieved Nov 1, 2026
- FTC – Do Not Call Reported Calls Data, 25 daily files 28 Sep – 30 Oct 2026, retrieved Nov 1, 2026
NANPA dialing note for this code: “10D”. Reviewed by the data desk. Spotted an error? Request a correction.