U.S. postal lookup

U.S. ZIP Codes Database 2026

Search by ZIP code, city, county, or state and find clear postal details with maps, time zones, and area code data.

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Connecticut ZIP Codes

Complete postal directory, details, and geographic map for the State of Connecticut.

State ZIP Code City County Area Codes
CT 06416 Cromwell Middlesex County 860, 959
CT 06417 Deep River Middlesex County 860, 959
CT 06418 Derby New Haven County 203, 475
CT 06419 Killingworth Middlesex County 203, 475, 860, 959
CT 06420 Salem New London County 860, 959
CT 06422 Durham Middlesex County 203, 475, 860, 959
CT 06423 East Haddam Middlesex County 860, 959
CT 06424 East Hampton Middlesex County 860, 959
CT 06426 Essex Middlesex County 860, 959
CT 06437 Guilford New Haven County 203, 475, 860, 959
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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.