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.

42,735 verified records
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California ZIP Codes

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

State ZIP Code City County Area Codes
CA 94583 San Ramon Contra Costa County 341, 510, 925
CA 94585 Suisun City Solano County 279, 707, 916
CA 94586 Sunol Alameda County 341, 510, 925
CA 94587 Union City Alameda County 341, 510
CA 94588 Pleasanton Alameda County 341, 510, 925
CA 94589 Vallejo Solano County 707
CA 94590 Vallejo Solano County 341, 510, 707
CA 94591 Vallejo Solano County 707
CA 94592 Vallejo Solano County 707
CA 94595 Walnut Creek Contra Costa County 925
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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.