351 Area Code: A Complete Guide to Lowell and the Merrimack Valley

On this page:

• Where Is the 351 Area Code Located?
• Cities and Communities Covered by the 351 Prefix
• Time Zone and Dialing Format for Merrimack Valley Numbers
• Calling a 351 Number From Outside the United States
• The Business Landscape Behind the Merrimack Valley's Local Numbers
• Why Your Business Needs a 351 Area Code Virtual Number
• The Bottom Line on Getting a 351 Number
• Frequently Asked Questions

Long before area codes ever existed, Lowell was already known for something else entirely: it's where the American Industrial Revolution effectively started, its mills running on Merrimack River power a century before anyone dialed a phone number. Today, a 351 area code number still carries that same regional identity forward.

This guide covers exactly where 351 reaches, how it overlays the older 978 code, and what the Merrimack Valley's business scene actually looks like today. We'll also show how a virtual 351 area code phone number lets a remote team answer and route calls like they're sitting downtown in Lowell.

Where Is the 351 Area Code Located?

The 351 area code covers northeastern Massachusetts, including Lowell, Lawrence, Haverhill, and Salem. It was activated in 2001 as an overlay to the existing 978 code, meaning both prefixes serve the exact same region side by side.

978 itself split off from 508 in 1997 to cover the growing area north and west of Boston. Within just four years, that territory needed its own overlay, a sign of how quickly the Merrimack Valley's population rebounded after decades of industrial decline.

From Mill Towns to a Modern Numbering Region

The same cities that once ran the country's textile industry, Lowell and Lawrence chief among them, are the ones driving demand for new phone lines today, as old mill buildings convert into offices, apartments, and studio space.

Porting a Number Into the 351 Overlay

If your business already carries an existing 978 number, you can add a 351 line without giving up the original. letsdial ports existing numbers in for free, both directions, so switching providers never means losing a number your customers already know. More detail sits on our letsdial page.

Cities and Communities Covered by the 351 Prefix

351 numbers issue across a broad stretch of northeastern Massachusetts rather than a single city. Here's where a local number puts your business on the map:

• Lowell: historic mills, higher education, small business
• Lawrence & Haverhill: manufacturing, immigrant-owned business
• Andover & North Andover: corporate offices, professional services
• Salem: tourism, retail, small business
• Fitchburg & Leominster: plastics manufacturing, logistics
• Newburyport & Gloucester: fishing, tourism, hospitality

Every city on that list shares the same overlay pool with 978, so a number issued in Lawrence looks identical to one issued in Salem. For a growing business, that consistency matters more than the exact town it sits in.

A biotech office in Andover, a fishing supplier in Gloucester, and a tourism business in Salem all dial out and answer in on the same 10-digit format, which keeps onboarding simple no matter which part of the region a growing team actually sits in. More detail sits on our AI receptionist page.

Time Zone and Dialing Format for Merrimack Valley Numbers

Every number on this exchange runs on Eastern Time, UTC-5 in winter and UTC-4 during daylight saving, the same zone as Boston and New York. A 9 a.m. call placed from Los Angeles lands at noon on a Lowell desk.

• Country code: +1
• Area code: 351
• Local number: XXX-XXXX
• Full dial-out: +1-351-XXX-XXXX
• Local dialing rule: 10-digit required across 978 / 351

Skip a digit and the call simply won't connect, even between two desks in the same building. Voice quality doesn't change based on which of the two overlay codes a number carries, so there's no technical downside to picking 351 over the older 978, and both route through the same carrier network.

Calling a 351 Number From Outside the United States

Reaching a Lowell line from abroad follows the standard North American pattern: exit code, then country code 1, then the area code, then the seven-digit local number.

• Country code: +1
• Area code: 351
• Local number: XXX-XXXX
• Full dial-out: +1-351-XXX-XXXX
• Local dialing rule: 10-digit required across 978 / 351

For a caller in Dubai that's 00, then 1, then 351, then the line. Drop any leading zero — North American numbers never take one. Get the sequence right and the call rings through to Lowell as cleanly as one placed from across the street.

Every Code in the Overlay Shares One Dial-In Format

Whether a line answers on 978 / 351 doesn't change how an international call reaches it — every code sharing this territory uses the identical +1 format, so getting the area code right matters far more than knowing which specific prefix a business happens to hold.

The Business Landscape Behind the Merrimack Valley's Local Numbers

Lowell's mill buildings, once the engine of American textile manufacturing, now house offices, startups, and UMass Lowell's growing research programs, a genuine second life for the city's industrial architecture.

Defense and electronics firms have deep roots in Andover and North Andover, tracing back to the region's Digital Equipment Corporation legacy, and that engineering talent base still draws employers to the area today, from established contractors to smaller software teams.

A Fishing and Tourism Economy Along the Coast

Gloucester's fishing fleet and Salem's witch-trial history pull steady tourism traffic to the region's coastal towns, supporting hospitality and retail businesses well beyond the summer season.

Plastics and Manufacturing in Fitchburg and Leominster

Fitchburg and Leominster carry a long plastics-manufacturing history, once earning Leominster the nickname Pioneer Plastics City, and that industrial base still supports logistics and light manufacturing across the region today.

What This Means for a New Business Line

A local number signals right away that you're inside that particular community, not calling in from somewhere else entirely. For sales teams targeting Massachusetts accounts or support desks fielding Merrimack Valley clients, an out-of-state prefix is often the reason a call gets screened before it even rings twice.

Remote Teams Are Driving Demand for Local Numbers

Plenty of the businesses picking up 351 numbers today have no office in the region at all. A distributed sales team can carry a 351 line the same way it carries a Slack workspace: as one more tool that follows the person, not the building.

Higher Education Anchoring the Local Workforce

UMass Lowell feeds a steady pipeline of engineers and healthcare graduates into the region's employers, reinforcing the same mix of legacy manufacturing and modern research that defines the entire valley today.

Why Your Business Needs a 351 Area Code Virtual Number

Caller-behavior data consistently shows unfamiliar area codes get ignored. A local 351 number changes that instantly for Merrimack Valley-based leads, giving you regional credibility without paying for a Lowell office, and letting your team answer from anywhere with an internet connection.

letsdial issues a virtual 351 area code phone number in minutes, no hardware and no on-site line required. Every plan includes intelligent call routing that sends Merrimack Valley callers straight to the right rep, plus an AI receptionist that answers, books, and logs the call to your CRM after hours.

• Pick a Merrimack Valley number and go live in under 3 minutes, no credit card required
• Port an existing 978 or 351 number in for free, both directions
• Every call transcribed automatically, with AI summaries attached in seconds
• One login covers calling, SMS, video, and team chat for the whole 351 line
• SOC 2 Type II, HIPAA, and PCI DSS compliance on every plan, not a bigger-plan perk

Setup runs through letsdial's UCaaS platform, so the same login also carries team chat, SMS, and video, one invoice instead of five vendor bills for a Merrimack Valley presence. A remote rep in Haverhill and a support agent in Andover can both answer the same 351 line without either one owning a desk phone, and a founder can run the whole setup from a laptop between client visits.

Pricing on the entry-level Starter plan starts at $7.99 per user per month, billed annually, with unlimited US and Canada calling and a Merrimack Valley number included from day one. There's no separate charge for the AI receptionist minutes bundled into every paid tier, so a busy front desk doesn't rack up a surprise monthly invoice at the end of the billing cycle.

> [TIP] Claim a Lowell-area number and start the free trial, live in under 3 minutes, no credit card required. That record is published in full as public record for area code 351.

The Bottom Line on Getting a 351 Number

A 351 area code number puts your business inside the Merrimack Valley without a Lowell lease, the kind of local presence Lawrence, Salem, and Andover callers actually pick up for. letsdial turns that number into a full phone system, AI receptionist included, under one login, so start the free trial today and claim your 351 number before a competitor does.

Frequently Asked Questions