Area Code 351

Massachusetts (MA) * Lowell, Haverhill, Lawrence, Acton, Amesbury, Andover, Ashburnham, Ashby * Eastern Time (ET)

1.4M

Population

ZIP codes

Massachusetts

Primary state

Eastern Time (ET)

Time zones

What stands out

Coverage: 1.4M people across 99 ZIP codes.
Overlapping area codes: 978
Major cities: Lowell, Haverhill, Lawrence.

Primary state:Massachusetts (MA)Major cities:Lowell, Haverhill, Lawrence, Acton, Amesbury, Andover, Ashburnham, Ashby

Browse sections

Basics

Percentiles compare this area code to other area codes nationwide.

Population

1.4M

ZIP codes

Median age

41.7 yrs

Population density

798.7/sq mi

Mean commute time

29 min

Avg. household size

2.6

Neighbors

Neighboring area codes

339 413 508 603 774 781 978

Notes & Sources

Area-code boundaries can change over time; verify official assignments with NANPA for critical use.
In regions with overlapping area codes, new numbers may use a different code.
This page aggregates ZIP-based crosswalks for orientation and does not indicate phone-number availability.

Data freshness

ACS 5-year: 2020–2024
Page updated: 2026-02-23

Release schedule and upstream dates: Sources.

Data sources

U.S. Census (ACS 5-year)U.S. Census TIGER/LineNANPA

Derived statistics

Area codes are not Census geographies; statistics are estimated by aggregating ZCTA (ZIP) values for associated ZIPs.
ZIP↔area code associations are derived from NPA boundary polygons and ZCTA centroid points, and can be approximate.
Median age, mean commute, and household size are population-weighted; population density uses summed ZIP land area.

Area code overlays and service areas are primarily governed by NANPA; this page uses aggregated geographic overlays for orientation only.

Data accuracy & methodology

This report aggregates 2020–2024 ACS 5-year estimates and geographic overlays for orientation. Area code service areas can cross ZIP/state boundaries and change over time; verify official assignments with NANPA for critical use.

Browse sections