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
94549 California Contra Costa Lafayette 1
94550 California Alameda Livermore 1
94551 California Alameda Livermore 1
94552 California Alameda Castro Valley 1
94553 California Contra Costa Martinez 1
94555 California Alameda Fremont 1
94556 California Contra Costa Moraga 1
94557 California Alameda Hayward 1
94558 California Napa Napa 1
94559 California Napa Napa 1
94560 California Alameda Newark 1
94561 California Contra Costa Oakley 1
94562 California Napa Oakville 1
94563 California Contra Costa Orinda 1
94564 California Contra Costa Pinole 1
94565 California Contra Costa Pittsburg 1
94566 California Alameda Pleasanton 1
94567 California Napa Pope Valley 1
94568 California Alameda Dublin 1
94569 California Contra Costa Port Costa 1
94570 California Contra Costa Moraga 1
94571 California Solano Rio Vista 1
94572 California Contra Costa Rodeo 1
94573 California Napa Rutherford 1
94574 California Napa Saint Helena 1
94575 California Contra Costa Moraga 1
94576 California Napa Deer Park 1
94577 California Alameda San Leandro 1
94578 California Alameda San Leandro 1
94579 California Alameda San Leandro 1
94580 California Alameda San Lorenzo 1
94581 California Napa Napa 1
94583 California Contra Costa San Ramon 1
94585 California Solano Suisun City 1
94586 California Alameda Sunol 1
94587 California Alameda Union City 1
94588 California Alameda Pleasanton 1
94589 California Solano Vallejo 1
94590 California Solano Vallejo 1
94591 California Solano Vallejo 1
94592 California Solano Vallejo 1
94595 California Contra Costa Walnut Creek 1
94596 California Contra Costa Walnut Creek 1
94597 California Contra Costa Walnut Creek 1
94598 California Contra Costa Walnut Creek 1
94599 California Napa Yountville 1
94601 California Alameda Oakland 1
94602 California Alameda Oakland 1
94603 California Alameda Oakland 1
94604 California Alameda Oakland 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.