North American Numbers Source-cited · ownership disclosed
Area code
781
In service
United States · since 1997

Boston suburbs (Route 128 corridor)

Area code 781 serves Boston's inner and outer suburbs along the Route 128 corridor and the South Shore. It was split from 617 in 1997 and is now overlaid by 339.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Boston suburbs (Route 128 corridor)
Type
geographic
Status
in service
In service since
1997
Projected exhaust
2156 Q2

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 781 is

Essex, Middlesex, Norfolk, Plymouth, and Suffolk counties (Route 128 corridor and South Shore)..

Communities served wholly or partly by 781:

WalthamWoburnLynnWeymouthDedhamMaldenMedfordRevereWakefieldLexington

The 781 region encircles the 617/857 inner-Boston area.

B · Relationships

How it relates to other codes

The codes 781 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Split from · 1997 617 Boston 781 split from 617 on September 1, 1997.
Overlay · 2001 339 Boston northern/inner suburbs (overlay) 339 overlays 781 across the same territory.
What's changing. Overlay complex with 339; ten-digit dialing mandatory. Per Wikipedia, exhaustion not projected until c. 2156.
C · History

How 781 got here

1997-09-01
Area code 781 created as a split from 617.
Source: Wikipedia
1998-02-01
Mandatory use of 781 began.
Source: Wikipedia
2001-05-02
Area code 339 added as an overlay; ten-digit dialing mandatory.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
795
Prefixes available
5
Thousands-blocks assigned
3,320

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 781 with another code →
Sources
Wikipedia ↗
Area code 781
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.