Area code 351: Massachusetts
Area code 351 is a US state area code for Massachusetts, on Eastern Time. It has 90 prefixes in service across 42 rate centers, the largest being Acton, Lowell and Danvers. It shares its area with 978, so local numbers there can start with any of them. Local calls there take 10 digits.
Local time in area code 351
America/New_York
Prefixes in service
90 of 792 possible
42 rate centers
Area code 351 facts
| Location | Massachusetts, United States |
|---|---|
| Time zone | Eastern Time |
| Overlays | 978 |
| Overlay of | 978 |
| In service since | May 2, 2001 |
| Local calls | 10 digits; toll calls 1 + 10 digits |
| Carrier | Not shown. An area code is where a number was issued; numbers port between carriers. Check line type |
Which cities and towns use area code 351?
NANPA records each prefix against a rate center, the local billing area a number belongs to, usually named after its main town. These are the 351 rate centers with the most prefixes in service. 30 smaller ones aren't listed.
| Rate center | Prefixes |
|---|---|
| Acton | 6 |
| Lowell | 5 |
| Danvers | 4 |
| Lawrence | 4 |
| Georgetown | 4 |
| Haverhill | 4 |
| Ashby | 3 |
| Gloucester | 3 |
| Merrimac | 3 |
| Harvard | 3 |
| Ipswich | 3 |
| Peabody | 3 |
Source: NANPA central office code assignments, file dated 10/17/2026. Each prefix holds up to 10,000 numbers.
How do I dial a 351 number?
NANPA's dialling plan for 351: local calls inside the code take 10 digits, toll calls 1 + 10 digits. From another area code, dial 1 first. From abroad, use +1. The examples use 555-0147, from a range reserved for fictional numbers.
| Local call inside 351 | 351-555-0147 |
|---|---|
| From another US or Canadian area code | 1-351-555-0147 |
| From outside North America | +1 351 555 0147 |
| E.164, for CRMs and SMS tools | +13515550147 |
When did area code 351 start?
Area code 351 went into service on May 2, 2001 as an overlay of 978. Today 351 and 978 cover the same area as an overlay, which is why 10-digit dialling is needed for local calls there.
Tools for 351 numbers
- Area code lookup
Look up any code or a whole list of numbers, or find the codes for a state or city.
- Area code time zone
Local time for a list of numbers, with a callable-now flag.
- NPA-NXX lookup
Rate center and state for one prefix, a level below the area code.
- TCPA calling hours checker
Whether it's inside the federal 8 a.m. to 9 p.m. calling window there now.
Next step
A 351 number tells you where it was issued, not what it is now.
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Area code 351 questions
- What state is area code 351?
- Area code 351 is in Massachusetts, United States. Its largest rate centers by number of prefixes are Acton, Lowell, Danvers, Lawrence and Georgetown.
- What time zone is area code 351 in?
- Eastern Time.
- What area codes overlay 351?
- 978. An overlay adds a new code to the same area instead of splitting it, so neighbours can have different area codes and local calls need 10 digits.
- When did area code 351 start?
- Area code 351 went into service on May 2, 2001 as an overlay of 978.
- Is a 351 number a cell phone or a landline?
- The area code can't tell you. In the US and Canada mobiles, landlines and VoIP lines share area codes and prefixes, and numbers move between carriers and line types. Only a live line-type lookup answers it for one number.
- How many phone numbers does area code 351 have?
- 90 of its 792 possible prefixes are in service, and each prefix holds up to 10,000 numbers. That counts prefixes assigned to carriers, not numbers in use.
Other area codes in Massachusetts
Sources
Location, overlays, in-service date and dialling plan: NANPA NPA database, file dated 10/16/2026. Prefixes and rate centers: NANPA central office code assignments, 10/17/2026. Time zones mapped to the IANA time zone database. By the SimpleVerifier Team; how we build these pages.