ZIP codes

ZIP codes in Delaware by county

Delaware has 68 ZIP codes in its 3 counties. 6 of them cross a county line and 1 cross into a neighboring state. New Castle County has the most, 31.

By the All Map Tools Team

ZIP codes: 68; With 1% or more of their land in the state
Counties: 3; 3 with a page of their own below
Cross a county line: 6; 1% or more of their land in another county
Cross a state line: 1; 1% or more of their land in another state
County with the most: 31; New Castle County
Most populated ZIP: 19720; 62,392 people · New Castle

ZIP codes per county in Delaware

19
20–23
24–31

Open in the interactive tool

Counties and their ZIP codes

County	Population (2025)	ZIP codes	Shared
Kent County	194,786	19	5
New Castle County	588,026	31	2
Sussex County	277,140	23	4

Every ZIP code in Delaware, by county

A ZIP code that crosses a county line appears in each county it has 1% or more of its land in.

Kent County (19): 19901, 19902, 19904, 19934, 19936, 19938, 19943, 19946, 19950, 19952, 19953, 19954, 19955, 19962, 19963, 19964, 19977, 19979, 19980
New Castle County (31): 19701, 19702, 19703, 19706, 19707, 19709, 19710, 19711, 19713, 19716, 19717, 19720, 19730, 19731, 19732, 19733, 19734, 19735, 19736, 19801, 19802, 19803, 19804, 19805, 19806, 19807, 19808, 19809, 19810, 19938, 19977
Sussex County (23): 19930, 19931, 19933, 19939, 19940, 19941, 19944, 19945, 19947, 19950, 19951, 19952, 19956, 19958, 19960, 19963, 19966, 19967, 19968, 19970, 19971, 19973, 19975

Neighboring states

Tools for Delaware

ZIP codes by county or city Any county or city in Delaware on an interactive map, with CSV US county map Its counties shaded by population, income or your own data Elevation and places of Delaware Its capital, its cities and its highest point, with their elevation

Sources

U.S. Census Bureau, 2020 ZCTA to County, ZCTA to Place and ZCTA to Census Tract Relationship Files (and the 2022 County Subdivision to ZCTA file for Connecticut). Public domain.
U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, table B01003 (population of each ZIP code, census tract and Connecticut town). Public domain.
U.S. Census Bureau, Vintage 2025 Population Estimates (county population) and 2025 Gazetteer Files (land area and interior point of each ZIP code). Public domain.
U.S. Census Bureau, Cartographic Boundary Files: ZCTAs 2020 and counties 2025, 1:500,000; county adjacency file 2025. Public domain.

How we count. ZIP codes here are the Census Bureau’s ZIP Code Tabulation Areas (ZCTAs), the areas it draws to match USPS ZIP codes; ZIPs with no area of their own (PO boxes, single buildings) aren’t included. A ZIP can cross county lines: “Land in the county” is the exact share of its land inside, from the Census relationship files. “Residents in the county” is the whole ZIP for those entirely inside; for shared ones it’s an estimate, spreading the people of each census tract over the land it shares with the ZIP. Population: ACS 2020–2024. Methodology.

Spotted a mistake? Let us know