Country Information

CountryUnited States
ISO CodeUS / USA
LanguageEnglish
Total Records42,605

United States uses a numeric code of 5 (or 5+4) digits (e.g. 10001). ZIP Code (5 digits) with optional ZIP+4 extension.

This database currently holds 42,605 ZIP Codes ranging from 00501 to 99929, linked to 0 building and address records. Because a single ZIP Code can cover more than one locality or delivery point, the lookup below groups addresses by code and lets you drill into the individual records.

Postal codes matter well beyond mail delivery. Couriers, e-commerce checkout forms and address autocomplete tools rely on the ZIP Code to route a parcel and to verify that the stated address matches the code. Addresses here are organised as State → County → City. The code itself is structured as ZIP Code → ZIP+4 → Delivery Point, which is postal geography and not the same as the administrative hierarchy. When you look up a code here, treat the associated name as a reference point rather than a full postal address — always confirm the street and house number with the sender or recipient before shipping.

Data source: a third-party open dataset. This is an imported reference dataset, not a live government feed; CodeReff does not independently verify each record, so codes may have changed since the snapshot was taken. Use the search box to look up a specific code, or browse the paginated table below.

United States Postcode Data

42,605 postcode found

Postal Code State County City Records
94406 California San Mateo San Mateo 1
94407 California San Mateo San Mateo 1
94408 California San Mateo San Mateo 1
94409 California San Mateo San Mateo 1
94497 California San Mateo San Mateo 1
94501 California Alameda Alameda 1
94502 California Alameda Alameda 1
94503 California Napa American Canyon 1
94506 California Contra Costa Danville 1
94507 California Contra Costa Alamo 1
94508 California Napa Angwin 1
94509 California Contra Costa Antioch 1
94510 California Solano Benicia 1
94511 California Contra Costa Bethel Island 1
94512 California Solano Birds Landing 1
94513 California Contra Costa Brentwood 1
94514 California Contra Costa Byron 1
94515 California Napa Calistoga 1
94516 California Contra Costa Canyon 1
94517 California Contra Costa Clayton 1
94518 California Contra Costa Concord 1
94519 California Contra Costa Concord 1
94520 California Contra Costa Concord 1
94521 California Contra Costa Concord 1
94522 California Contra Costa Concord 1
94523 California Contra Costa Pleasant Hill 1
94524 California Contra Costa Concord 1
94525 California Contra Costa Crockett 1
94526 California Contra Costa Danville 1
94527 California Contra Costa Concord 1
94528 California Contra Costa Diablo 1
94529 California Contra Costa Concord 1
94530 California Contra Costa El Cerrito 1
94531 California Contra Costa Antioch 1
94533 California Solano Fairfield 1
94534 California Solano Fairfield 1
94535 California Solano Travis Air Force Base 1
94536 California Alameda Fremont 1
94537 California Alameda Fremont 1
94538 California Alameda Fremont 1
94539 California Alameda Fremont 1
94540 California Alameda Hayward 1
94541 California Alameda Hayward 1
94542 California Alameda Hayward 1
94543 California Alameda Hayward 1
94544 California Alameda Hayward 1
94545 California Alameda Hayward 1
94546 California Alameda Castro Valley 1
94547 California Contra Costa Hercules 1
94548 California Contra Costa Knightsen 1

Postcodes by Region

Postcodes by City

Frequently Asked Questions

United States uses a numeric code of 5 (or 5+4) digits (e.g. 10001). ZIP Code (5 digits) with optional ZIP+4 extension.
Yes. United States postal codes are a plain numeric string, so a leading zero is part of the code itself. A code beginning with 0 must be written and stored with that zero — it is not the same as the same digits without it.
42,605 This database currently lists
The records are imported from a third-party open dataset, an open reference dataset. CodeReff does not independently verify each entry, so use the information as a reference rather than an official confirmation.
Enter a full or partial postal code, or a building or street name, in the search box above. You can also browse the paginated table and open any code to see its building and address records.
Information provided on CodeReff is for reference purposes only. Always verify financial and banking details with the relevant institution before use.