--- title: "Area code 351: Massachusetts, United States" url: "https://lookvalid.com/area-code/351.md" canonical_url: "https://lookvalid.com/area-code/351" last_updated: "2026-10-23" type: "reference" summary: "Area code 351 serves Massachusetts, United States. Number formats, numbering rules, a live phone validator and the other codes in Massachusetts." --- # Area code 351: Massachusetts, United States Area code 351 serves Massachusetts, United States. Number formats, numbering rules, a live phone validator and the other codes in Massachusetts. NANPA lists 90 central office codes (prefixes) in use in area code 351, held by 21 holders across 43 rate centers. Onvoy holds the most prefixes, 28 (31%). 99% of the prefixes are pooled, which means their thousands-blocks can belong to different companies. The FCC unwanted-call data has 548 complaints on file for 361 numbers in 351, most often filed as "Unwanted Calls". These are consumer reports, not findings. ## Facts - In service since: 2001-05-02 - Time zone: Eastern (E) - Assigned overlays: 978 (1997-09-01) - Prefixes in use: 90 - Pooled prefixes: 89 (99%) - Rate centers: 43 - Companies holding prefixes: 21 - Assignment dates on file: 2012-08-29 to 2025-03-04 (79 prefixes) - ZIP codes in its places: 57 ## Rate centers | Rate center | Prefixes | Share | | --- | --- | --- | | ACTON | 6 | 7% | | LOWELL | 5 | 6% | | DANVERS | 4 | 4% | | GEORGETOWN | 4 | 4% | | HAVERHILL | 4 | 4% | | LAWRENCE | 4 | 4% | | ASHBY | 3 | 3% | | GLOUCESTER | 3 | 3% | | 35 other rate centers | 57 | 63% | ## Carriers | Holder | Prefixes | Share | | --- | --- | --- | | Onvoy | 28 | 31% | | Fractel | 11 | 12% | | Omnipoint Miami E License | 10 | 11% | | Ton80 Communications | 7 | 8% | | Onvoy Spectrum | 5 | 6% | | Verizon Wireless | 4 | 4% | | 15 other carriers | 25 | 28% | A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company. ## History - 1997-09-01: Area code 978, named as the parent of 351 in the NANPA report, was in service. - 2001-05-02: Area code 351 went into service. ## Nearest area codes The area codes closest to 351, measured between the centers of the ZIP code places they serve, are 617 (about 23 miles), 857 (about 23 miles), 339 (about 25 miles), 781 (about 25 miles) and 508 (about 37 miles). ## ZIP codes 57 ZIP codes fall in places that have a rate center in this area code. The places with the most are Andover, MA (5 ZIP codes), Lowell, MA (5 ZIP codes) and Haverhill, MA (4 ZIP codes). A ZIP code and an area code are unrelated systems, so a ZIP code can sit in more than one area code and an area code spans many ZIP codes. ## Complaints on file 548 complaints for 361 numbers. Numbers whose latest complaint falls in each year: - 2023: 47 - 2024: 45 - 2025: 25 ## Questions ### Where is area code 351? NANPA assigns area code 351 to Massachusetts, United States. ### In which state does area code 351 sit? Massachusetts. 351 is one of 9 area codes the NANPA table assigns to the state. ### Which places does area code 351 cover? The places with the most ZIP codes among the rate centers in 351 are Andover, MA, Lowell, MA and Haverhill, MA. The rate center list on this page shows all of them. ### Who owns area code 351? NANPA assigns area codes. Within 351, Onvoy holds the most prefixes, 28 prefixes or 31%. ### Which time zone does 351 use? The NANPA NPA report lists the time zone for 351 as Eastern (E). ### What year did 351 enter service? The NANPA NPA report gives an in-service date of 2001-05-02, so 351 has been in use since 2001. ### Does area code 351 have an overlay? Yes. 978 (in service 1997-09-01) shares the same area with 351, so numbers from all of them are local to each other. ### Which area codes are nearest to 351? The area codes closest to 351, measured between the centers of the ZIP code places they serve, are 617 (about 23 miles), 857 (about 23 miles), 339 (about 25 miles), 781 (about 25 miles) and 508 (about 37 miles). ### How many prefixes does area code 351 have? NANPA's report dated 2026-10-17 lists 90 prefixes in service in 351, spread over 43 rate centers and 21 holders. ### Are there complaints about 351 numbers? The FCC data on file has 548 complaints for 361 numbers in 351. They are unverified consumer reports. A number with no complaints on file is not proven safe. Sources: NANPA central office code report dated 2026-10-17; NANPA NPA report dated 2026-10-18; FCC unwanted-call complaints, data fetched 2026-10-17; ZIP code places from GeoNames (CC BY 4.0).