ZIP Code 03878

03878 is one of New Hampshire's ZIP codes, delivering to addresses in Somersworth, Strafford County.

City: Somersworth
County: Strafford County
State: New Hampshire
Prefix: 038xx

Where this code sits

03878 is part of the 038xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Somersworth.

Somersworth New Hampshire ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 03878 delivers to without sharing its boundary.

603 Area code 603

ZIP codes nearest 03878

The ZIP codes whose reference points sit closest to 03878.
ZIP code	Distance	Delivers to
ZIP code 03869	2.8 mi	Rollinsford, NH
ZIP code 03901	2.8 mi	Berwick, ME
ZIP code 03821	3.8 mi	Dover, NH
ZIP code 03822	3.8 mi	Dover, NH
ZIP code 03820	4.4 mi	Dover, NH
ZIP code 03908	4.8 mi	South Berwick, ME
ZIP code 03839	5.5 mi	Rochester, NH
ZIP code 03868	5.7 mi	Rochester, NH

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 03878, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope ZIP code 03878. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.