351 Area Code: Lowell, Massachusetts

Massachusetts's 351 area code is an overlay sharing geography with the long-running 978, layered onto the cities and towns north and west of Boston. Lowell, on the Merrimack River, anchors the directory's records here. Lowell was one of the first planned industrial cities in the country — the early-nineteenth-century mills along the river drew water power for what became one of the largest textile-manufacturing operations in the world, and the rebuilt mill complexes still organize the city's downtown. The 351 footprint reaches through Lawrence, Haverhill, Andover, and the surrounding Merrimack Valley and north-suburban communities.

In records the directory has compiled for 351 numbers, other Massachusetts cities — Boston, Quincy, Springfield, and Worcester — appear regularly. None of those are inside the 351 footprint. The pattern reflects standard public-record dynamics, with phone numbers porting across Massachusetts and addresses linked across multiple cities. The directory currently documents 17 distinct prefixes within 351 in detail, a working subset of the prefix population the code carries.

Lowell's home values come in roughly above the US median, in line with broader eastern Massachusetts pricing pressure. Median household income runs close to the national reading, the city's median age sits a few years under the US figure, and population places Lowell among the larger Massachusetts cities outside Boston itself. The 351 footprint shares those demographics with 978 because both codes serve the Merrimack Valley and north-suburban Boston region in overlapping form.