ZIP Code 03837

03837 is one of New Hampshire's ZIP codes, delivering to addresses in Gilmanton Iron Works, Belknap County.

City: Gilmanton Iron Works
County: Belknap County
State: New Hampshire
Prefix: 038xx

Where this code sits

03837 is part of the 038xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Gilmanton Iron Works.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 03837 delivers to without sharing its boundary.

603 Area code 603

ZIP codes nearest 03837

The ZIP codes whose reference points sit closest to 03837.
ZIP code	Distance	Delivers to
ZIP code 03810	3.6 mi	Alton Bay, NH
ZIP code 03809	3.7 mi	Alton, NH
ZIP code 03237	6.0 mi	Gilmanton, NH
ZIP code 03225	6.8 mi	Center Barnstead, NH
ZIP code 03218	7.7 mi	Barnstead, NH
ZIP code 03855	8.0 mi	New Durham, NH
ZIP code 03249	8.8 mi	Gilford, NH
ZIP code 03298	9.1 mi	Tilton, 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 03837, plotted from its record coordinates.

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

Scope ZIP code 03837. 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.