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U.S. ZIP Codes Database 2026

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Loudoun County ZIP Codes

Browse all ZIP Codes, cities, and associated area codes registered in Loudoun County.

County State ZIP Code City Area Codes
Loudoun County VA 20178 Leesburg 571
Loudoun County VA 20180 Lovettsville 227, 240, 301, 540, 571, 703, 826
Loudoun County VA 20189 Dulles 571, 703
Loudoun County VA 20197 Waterford 540, 571, 703, 826
Loudoun County VA 20199 Dulles 571
Loudoun County VA 22093 Ashburn 571
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About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.