ZIP Codes in Delaware
Delaware is the second-smallest state in the country by land area, and its ZIP code map reflects that compactness - the entire state fits within just three counties, and even its longest north-south drive takes only a couple of hours. With around 1 million residents, Delaware's postal geography is dominated by the Wilmington area in the north, close to Philadelphia and the mid-Atlantic corridor, while the southern half of the state slows down considerably into farmland and beach towns.
How ZIP Codes Are Organized Across the State
Delaware's ZIP codes fall within the 19700–19999 range under the USPS system, one of the smallest numeric ranges of any state given Delaware's size. Wilmington and the surrounding New Castle County area sit around 198xx, Dover, the state capital, occupies 199xx, and the southern beach towns near Rehoboth and Lewes carry codes toward the upper end of that same range.
Delaware's Major Population Centers
The chart below shows how population concentrates around Wilmington in the north, with the rest of the state's cities considerably smaller by comparison.
Wilmington's ZIP codes cover Delaware's largest city and its financial and corporate hub - the state's famously business-friendly incorporation laws mean a huge number of US companies are legally registered here, even though most have no physical office in the state. Newark, home to the University of Delaware, sits just southwest of Wilmington and carries a distinctly college-town character. For a broader national comparison, our full US ZIP code directory shows how Delaware's compact range compares to every other state.
Dover and Central Delaware
Dover, the state capital, anchors central Delaware with a mix of state government offices, Dover Air Force Base, and a growing residential population as more people relocate south from the pricier Wilmington area. ZIP codes here cover a transition zone between the dense northern corridor and the more agricultural land further south, with Middletown standing out as one of the fastest-growing towns in the entire state over the past decade.
Southern Delaware and the Beach Towns
Delaware's southern beach towns - Rehoboth Beach, Lewes, and Bethany Beach among them - see enormous seasonal population swings, with summer tourist traffic dwarfing the year-round resident count captured in standard population figures. ZIP codes here also tend to carry some of the highest property values in the state, driven by demand from vacation-home buyers coming down from the DC and Philadelphia metro areas.
Why ZIP Codes Matter Beyond Mail
In Delaware, ZIP codes carry particular significance for the corporate and legal sectors, given how many businesses are incorporated in the state without maintaining a physical presence there - Wilmington-area ZIP codes in particular are closely tied to the state's Court of Chancery and corporate law industry. Real estate listings in the beach towns lean heavily on ZIP codes to signal proximity to the coast, which can significantly affect property values even over short distances.
Border Regions and Neighboring States
Delaware shares borders with three states despite its small size. To the north, Wilmington sits close enough to Pennsylvania that many residents commute into Philadelphia for work. To the west, the border with Maryland runs through farmland that looks similar on both sides, particularly around the Delmarva Peninsula. And to the south, that same peninsula continues into Maryland's Eastern Shore, sharing a comparable mix of agriculture and coastal tourism.
Finding the Right ZIP Code
Use the list below to browse Delaware's ZIP codes by city, county, or population - sorted so the most populous areas surface first. Each entry links through to a detailed page with additional demographic data. If you're trying to identify the ZIP code for a specific address rather than browsing by city, the search tool at the top of this page will get you there faster than scrolling through the full list.
Frequently Asked Questions
How many ZIP codes does Delaware have?
Delaware has around 65 ZIP codes, one of the smallest counts of any state, reflecting its compact size and limited number of counties.
What ZIP code range does Delaware use?
Delaware ZIP codes fall between 19700 and 19999, with Wilmington toward the lower end and Dover and the southern beach towns further along the range.
Why are so many US companies incorporated in Delaware?
Delaware's business-friendly corporate law and specialized Court of Chancery make it a popular incorporation state, even for companies with no physical office there - most of that activity is centered around Wilmington-area ZIP codes.
Can I look up a Delaware ZIP code by city name?
Yes, use the search tool on this page or browse the full list below, which is organized by city and sorted by population.
Whether you're relocating to Wilmington's corporate corridor, researching a beach town property near Rehoboth, or simply trying to pin down the right ZIP code for a specific Delaware address, the data below covers the entire state - from the Pennsylvania line to the southern coast.