ZIP Code 21640

21640 is one of Maryland's ZIP codes, delivering to addresses in Henderson, Caroline County.

City: Henderson
County: Caroline County
State: Maryland
Prefix: 216xx

Where this code sits

21640 is part of the 216xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Henderson.

Henderson Maryland ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 21640 delivers to without sharing its boundary.

ZIP codes nearest 21640

The ZIP codes whose reference points sit closest to 21640.
ZIP code	Distance	Delivers to
ZIP code 21636	3.1 mi	Goldsboro, MD
ZIP code 21649	3.3 mi	Marydel, MD
ZIP code 19964	4.2 mi	Marydel, DE
ZIP code 21670	5.0 mi	Templeville, MD
ZIP code 21607	5.6 mi	Barclay, MD
ZIP code 21644	5.6 mi	Ingleside, MD
ZIP code 21639	7.3 mi	Greensboro, MD
ZIP code 19953	8.1 mi	Hartly, DE

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 21640, plotted from its record coordinates.

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

Scope ZIP code 21640. 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.