Area Code 978 – Massachusetts

Overview of Area Code 978

Area code 978 is a geographic North American Numbering Plan (NANP) code serving a substantial portion of northeastern Massachusetts. It was introduced on July 1, 1997, as a split from area code 508, which had been overburdened by demand. The numbering plan area (NPA) 978 covers the counties of Essex, Middlesex, and Worcester, including the cities of Lowell, Lawrence, Haverhill, Peabody, and Woburn, as well as many suburban communities north and west of Boston. The region is characterized by a mix of urban centers, historic mill towns, and residential suburbs.

Dialing Formats and Procedures

Within the NANP, all calls to area code 978 require 10-digit dialing (area code + 7-digit local number) even for local calls, a practice mandated by the Federal Communications Commission (FCC) to accommodate overlay codes. For callers within the United States, Canada, and other NANP countries, the international format is +1 978 XXX XXXX. For callers from outside the NANP, the international access prefix of their country must be used, followed by 1, 978, and the seven-digit subscriber number. For example, a caller in London would dial 00 1 978 555 0123.

Geographic Coverage and Communities

The 978 area code serves numerous municipalities, including but not limited to Acton, Andover, Billerica, Chelmsford, Danvers, Fitchburg, Gloucester, Leominster, Methuen, Newburyport, North Andover, Salem, Tewksbury, and Wilmington. It also covers parts of the city of Boston’s northern suburbs, such as Malden and Medford, though these are split between 781 and 978. The region is home to a diverse economy, with industries ranging from healthcare and education to technology and manufacturing.

Overlay and Numbering Resources

To address the exhaustion of available numbers, area code 351 was introduced as an overlay to 978 in 2001. This means that new telephone lines in the same geographic region may be assigned either 978 or 351 numbers. Consequently, local calls between 978 and 351 numbers are not toll calls, but they do require 10-digit dialing. The overlay ensures that the region continues to have sufficient numbering resources without the need for another split, which would disrupt existing numbers.

Caller Instructions

For local callers within the 978/351 region, simply dial the 10-digit number (area code + seven digits). For long-distance calls within the United States, dial 1 + 10-digit number. For international callers, dial your country's exit code, then 1, then 978, then the seven-digit number. For example, from the UK, you would dial 00 1 978 555 0123. Always verify the number of the party you are calling, as some areas may have multiple area codes due to overlays.