Area Code 351
Massachusetts
Area code 351 serves Massachusetts, primarily Lowell, in the Eastern Time (ET) time zone. It is an overlay area code sharing territory with area code 978.
Published: Last reviewed: Verified against NANPA and FCC records
Overlay Area Code
This area code shares its geographic footprint with an overlay code, so the same cities are served by two area codes. Because overlays leave existing numbers untouched, this region's relief planning favors adding codes over redrawing boundaries.
The codes serving this same region: area code 978 (Lowell).
In service since: 02-May-2001
Demographics & Economics
- Total Population
- 884,136
- Population Density
- 294 people/sq miabove U.S. average (U.S.: 95 people/sq mi)
- Median Household Income
- $71,306below U.S. median (U.S.: $80,734)
- Poverty Rate
- 14.1%above U.S. average (U.S.: 12.5%)
- Unemployment Rate
- 5.7%near U.S. average (U.S.: 5.2%)
- Education Attainment
- Bachelor's Degree+36.5%near U.S. average (U.S.: 35.7%)High School or Lower31.6%
Statistics are population-weighted aggregations from Census ACS 5-year estimates. Population figures are approximate — see Sources & Methodology for details on how area code populations are derived.
See how this area code compares to all US area codes in the income ranking and density ranking.
Time Zone
- Eastern Time (ET)
NANPA Relief Status
According to the latest NANPA analysis (July 2026), this area code is not currently listed as exhausting within the next 36 months. No relief planning is in progress for this NPA.
Source: NANPA NPA Relief Planning Reports · See all relief planning statuses
Current Time
Prefix Utilization
Geographic Coverage
State
MA
Major Cities
- Lowell
- Lawrence
- Haverhill
- Peabody
- Salem
- Leominster
- Beverly
- Fitchburg
- Gloucester
- Danvers
- Wilmington
- Gardner
- Newburyport
- Hudson
- Maynard
- Andover
- Athol
- Clinton
- Pinehurst
- West Concord
- Salisbury
- Ipswich
- Rockport
- Winchendon
and 23 more cities
Historical Timeline of Area Code 351
Area code 351 was created on May 2, 2001, as an overlay for area code 978 in north central and northeastern Massachusetts. It was part of a simultaneous quad overlay: Massachusetts activated four new area codes (857, 774, 339, 351) on the same day, ordered by the Massachusetts Department of Telecommunications and Energy in April 2000. This coordinated approach addressed numbering exhaustion across Eastern Massachusetts, where rapid growth in the late 1990s depleted available prefixes in multiple overlapping area codes. Source: MA DTE D.T.E. 99-11
Key milestones:
- 1988: Area code 508 created from a 617 split (July 1988), serving eastern Massachusetts outside Boston. Source: NANPA
- 1997: Area code 978 created from a 508 split (September 1, 1997), covering north central and northeastern Massachusetts. Source: NANPA
- 1999: FCC 99-246 delegated authority to MA DTE for area code conservation (September 15, 1999). Source: FCC Delegation Order
- 2000: DTE ordered four overlays simultaneously: 857/617, 774/508, 339/781, 351/978 (April 25, 2000). NANPA issued Planning Letter 234 on July 11, 2000. Source: MA DTE D.T.E. 99-11
- 2000: Permissive 10-digit dialing began across Eastern Massachusetts (September 15, 2000). Source: NANPA PL-234
- 2001: Mandatory 10-digit dialing (April 2, 2001). Area code 351 activated as overlay of 978 (May 2, 2001). Source: NANPA PL-234
Regulatory History
Area code 351 was created through five significant regulatory events spanning from 1999 to 2001. The FCC delegated area code authority to Massachusetts DTE in 1999, which then ordered four overlays for Eastern Massachusetts in April 2000. NANPA issued Planning Letter 234 on July 11, 2000, assigning NPA 351 to overlay 978. Source: NANPA PL-234
| Year | Event | Docket | Regulatory Action & Impact |
|---|---|---|---|
| 1999 | Delegation Order | CC Docket No. 96-98 | FCC delegated authority to MA DTE for TNP and area code conservation for 508, 617, 781, 978. Source: FCC 99-246 |
| 2000 | Area Code Relief Order | D.T.E. 99-11 | Ordered creation of four overlays (857, 774, 339, 351); chose overlay over split due to industry support. Source: MA DTE |
| 2000 | TNP Investigation | D.T.E. 99-99 | Concluded TNP insufficient to delay new area codes; estimated $8M cost for early implementation. Source: MA DTE |
| 2000 | NPA Assignment | PL-234 | Assigned 351 as overlay of 978; permissive dialing Sep 15, 2000; mandatory Apr 2, 2001; in-service May 2, 2001. Source: NANPA |
| 2001 | NXX Rationing | Letter Order | Ordered 978 NXXs exhausted before 351 use; 34 pending 351 requests converted to 978. Source: MA DTE |
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 351).
| County | Population | Share |
|---|---|---|
| Essex, MA | 688,881 | 47.4% |
| Middlesex, MA | 507,486 | 34.9% |
| Worcester, MA | 229,611 | 15.8% |
| Franklin, MA | 26,523 | 1.8% |
Area Code 351 Family Tree
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Area code 351 was originally assigned in 02-May-2001 to serve MA.
Call Context
This area code serves a major metropolitan region with high population density in MA. The primary city is Lowell.
Nearby Area Codes
Area codes geographically closest to 351.
Other Area Codes in Massachusetts
Area codes that also serve Massachusetts, linked for easy comparison.