Area code 351

About area code 351

Area code 351 is a geographic area code in Massachusetts, in service since May 2, 2001, according to the North American Numbering Plan Administrator (NANPA). It is an overlay: 351 and 978 cover the same territory, so neighbors on the same street can have different area codes. It is in the Eastern time zone. The places with the most assigned exchanges include Acton, Lowell, Danvers, Lawrence, and Georgetown. By population, its largest named places are Lowell, Lawrence, Haverhill, Peabody, and Salem.

Places served by 351

351 holds 1.9% of the 4,743 central office codes assigned in Massachusetts, the 9th most of the state's 9 codes. 42 Census places could be matched to rate centers with 351 exchanges; the most populous are Lowell (120,000), Lawrence (89,332), Haverhill (68,291), and Peabody (55,418). Each place page lists the exact prefixes and carriers for that town.

How calls are dialed in 351

According to NANPA's dialing-plan data, local calls within 351 are dialed as ten digits (area code plus number) and toll calls as 1 plus ten digits. Because local calls need the area code, business cards, signage and website copy should always show the full ten-digit number. NANPA's dialing-plan note for this code reads: "1+10 digit permissible at service provider discretion"

Carriers with 351 numbers

22 carriers hold the 92 central office codes assigned in 351. Onvoy, LLC - Ma has the most, with 28 (30%). 90 of the codes (98%) are pooled, meaning the code holder shares blocks of 1,000 numbers with other carriers instead of using all 10,000 itself. The code holder is not necessarily the carrier serving a given number today, since numbers can be ported between providers.

Where 351 numbers are rated

NANPA assigns each central office code to a rate center, the local calling area that decides whether a call is local or toll. 351 has codes in 44 rate centers. Rate center names in the file are abbreviations; where one matches a Census place, the table links to that city's local-number page.

How full is area code 351?

An area code has 800 possible central office codes that start with 2 through 9, a few of which are reserved (such as N11 service codes and 555). 92 are assigned in 351, 12% of 800. 62 were assigned in 2020 or later.

Using area code 351 for business calls

Callata is a business phone system priced at $99 a month with 5 users included, then $20 per additional user. Callata Office includes up to 3 local business numbers, unlimited inbound calling, 1,500 pooled outbound US and Canada minutes per user each month, a browser softphone that can also ring your cell, voicemail with transcription, call recording with AI summaries, business-hours routing and E911 on every number.

Porting a number you already use in area code 351 is free, and business texting is available once the carrier registration (10DLC) is approved; the registration carries a one-time $49 fee. Which specific numbers are open in a given area code depends on carrier inventory at the time you sign up.

AI agents are optional: an AI receptionist or scheduler can pick up when the team is busy or closed, take a message, send a text or email, or transfer the call. They draw on prepaid AI minutes ($0.25/minute), disclose that they are AI, and outbound AI calls require prior consent and are limited to 8am–9pm.