ZIP Code 06423

06423 is one of Connecticut's ZIP codes, delivering to addresses in East Haddam, Lower Connecticut River Valley Planning Region.

City: East Haddam
Planning region: Lower Connecticut River Valley Planning Region
State: Connecticut
Prefix: 064xx

Where this code sits

06423 is part of the 064xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to East Haddam.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 06423 delivers to without sharing its boundary.

ZIP codes nearest 06423

The ZIP codes whose reference points sit closest to 06423.
ZIP code	Distance	Delivers to
ZIP code 06469	3.2 mi	Moodus, CT
ZIP code 06439	3.4 mi	Hadlyme, CT
ZIP code 06438	5.2 mi	Haddam, CT
ZIP code 06412	5.4 mi	Chester, CT
ZIP code 06417	6.8 mi	Deep River, CT
ZIP code 06420	7.2 mi	Salem, CT
ZIP code 06415	7.4 mi	Colchester, CT
ZIP code 06474	7.7 mi	North Westchester, CT

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 06423, plotted from its record coordinates.

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

Scope ZIP code 06423. 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.