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 94521 Concord Contra Costa County 925
CA 94522 Concord Contra Costa County 925
CA 94523 Pleasant Hill Contra Costa County 925
CA 94524 Concord Contra Costa County 925
CA 94525 Crockett Contra Costa County 341, 510
CA 94526 Danville Contra Costa County 925
CA 94527 Concord Contra Costa County 925
CA 94528 Diablo Contra Costa County 925
CA 94529 Concord Contra Costa County 925
CA 94530 El Cerrito Contra Costa County 341, 510
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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.