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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California ZIP Codes

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

State ZIP Code City County Area Codes
CA 94022 Los Altos Santa Clara County 408, 650, 669
CA 94023 Los Altos Santa Clara County 650
CA 94024 Los Altos Santa Clara County 408, 650, 669
CA 94025 Menlo Park San Mateo County 650
CA 94026 Menlo Park San Mateo County 650
CA 94027 Atherton San Mateo County 650
CA 94028 Portola Valley San Mateo County 650
CA 94030 Millbrae San Mateo County 650
CA 94035 Mountain View Santa Clara County 650
CA 94037 Montara San Mateo County 650
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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.