Random Delaware Address Generator

Three counties, three ZIP prefixes

Delaware has only three counties, the fewest of any state: New Castle in the north, Kent in the middle and Sussex in the south. Its ZIP codes are just as compact, 19701 to 19980: 197 for New Castle County outside Wilmington, 198 for Wilmington and 199 for Kent and Sussex. A county drop-down for Delaware should have exactly three entries; if your data source shows more, it is mixing in a neighbouring state.

Why Wilmington has so many ZIP codes

Wilmington has about 70,000 residents but 25 ZIP codes in the data we use. Many of them are unique ZIP codes assigned to a single organisation. After Delaware’s Financial Center Development Act of 1981 removed interest-rate caps, banks moved their credit card operations to Wilmington, and the state is also the legal home of most large US corporations. That is why so many card statements and corporate registered addresses point to Wilmington — and why a Wilmington ZIP code in your test data may belong to a bank rather than a street.

Same name, different state

Newark, Dover, Milford, Middletown and Georgetown all exist in other states — Newark, New Jersey, is far larger than Newark, Delaware. Delmar sits on the Delaware–Maryland line and has two ZIP codes, 19940 on the Delaware side and 21875 on the Maryland side. These are good test cases for autocomplete and for any logic that infers the state from the city name.

One area code

The whole state uses area code 302, assigned in 1947. Generated phone numbers are (302) 555-01xx, from the range reserved for fiction. If you need a second Delaware area code to test overlay handling, there is none — use a neighbouring state such as Maryland (410/443) instead.

Sales tax on a Delaware address

State rate: none. Delaware has no state or local sales tax. Instead, sellers pay a gross receipts tax on their own turnover, which is never shown on the customer’s receipt. A Delaware shipping address is therefore the clean test of a zero rate: the order total should equal the item total plus shipping, with no tax line at all.

Cities in the Delaware generator

The generator picks one of these 15 places, then one of its real ZIP codes and one of its area codes. Delaware has 96 ZIP codes in 57 places in the data we use.

Delaware ZIP code prefixes

The first three digits of a ZIP code identify the sectional center facility that sorts its mail. Delaware uses 3 prefixes; each is shown with the place that has most of its ZIP codes and how many codes it holds.

Delaware area codes

Phone numbers in generated addresses always use 555-0100 to 555-0199, the block the North American Numbering Plan reserves for fiction, so they never ring a real line.

Sources

• GeoNames US postal codes (CC BY 4.0): ZIP codes, places and counties
• North American Numbering Plan area code assignments
• Delaware Division of Revenue – gross receipts tax
• USPS Publication 28 – Postal Addressing Standards

Checked October 2026. Street names and house numbers in the generator are synthetic. General US address format, ZIP code structure and form-testing tips are on the US address generator page; ZIP codes on their own come from the ZIP code generator.

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