What is what area code is 351?

The 351 area code is an overlay of the 978 area code in Massachusetts, United States. It was established in 2001 to provide additional phone number options in the region. The cities and towns covered by the 351 area code include Lowell, Lawrence, Fitchburg, Leominster, Haverhill, and several other communities in northeastern Massachusetts. The 978 area code covers most of the northeastern and central part of the state, including the cities of Worcester and Salem. Both area codes are administered by the North American Numbering Plan Administration (NANPA).