GeoNames Postal Code dataset — US subset

Attribution: Contains modified GeoNames postal-code data. Source: GeoNames, https://www.geonames.org/
Source archive: https://download.geonames.org/export/zip/US.zip
Dataset documentation: https://download.geonames.org/export/zip/readme.txt
Retrieved on: 2026-10-09 (Europe/Paris session date)
Source archive Last-Modified: Fri, 09 Oct 2026 02:51:19 GMT
Source archive SHA-256: b92e2e9d2a4fac6b7fea92c5378fe0dc503d7da5eca740a6096b3bc3a7aa0cd3

License: Creative Commons Attribution 4.0 International (CC BY 4.0), as explicitly declared by the postal-code README.
License link: https://creativecommons.org/licenses/by/4.0/
GeoNames data-use terms: https://www.geonames.org/export/
The upstream README also retains a legacy link to the CC BY 3.0 deed; its license declaration names version 4.0. Both source references are retained here for traceability.
Legacy upstream link: https://creativecommons.org/licenses/by/3.0/
GeoNames permits commercial reuse with attribution. This notice credits the source and identifies the modifications; no GeoNames endorsement is implied.
Keep this attribution/license notice distributed and accessible with us-postal-places.json.

Format and modifications:
The upstream archive contains UTF-8, tab-delimited records with 12 fields. This derivative keeps postal code (field 2), place name (field 3), first-level administration name (field 4), and first-level administration code (field 5).
Compact output is a JSON object keyed by the original 5-character ZIP string, with {city,state,code} values. Leading zeroes are retained. County, community, coordinates, and accuracy fields were omitted. Records with the same ZIP are grouped; distinct place names are joined with ' / ' in source order. This is not an assertion of a USPS-preferred city name.
For multi-name ZIPs, the only non-empty state and code reported by the source are retained. Empty state fields remain empty; state values are never inferred from ZIP prefixes or military labels.

Counts:
Source records: 41490
Unique ZIP entries: 41488
Multi-name ZIPs: 2
Entries without state/code: 509
JSON size: 2484987 bytes
JSON SHA-256: 7c9b73697c4fd08918af1ef8b32ceeb83109f61fe78271da2411e9f848b0a46f

Grouped ambiguous records:
96860: Jbphh / FPO AA; geographic source record Hawaii/HI, military source record has no state/code.
96863: Mcbh Kaneohe Bay / FPO AA; geographic source record Hawaii/HI, military source record has no state/code.

Use and limitations:
Use only as a place-name suggestion while preparing a request. A ZIP missing from the file must remain usable; absence does not establish that a ZIP is invalid. Users must be able to correct or enter their location manually.
GeoNames supplies the data as-is without guarantees of accuracy, timeliness, or completeness. This is a GeoNames extract, not an official USPS address-verification service or delivery eligibility database.
Only the GeoNames US.zip subset is included; other separate territorial/country extracts were not imported. The source includes military labels with empty administration fields and two MH-coded entries, which are preserved without making any claim of commercial delivery coverage.
A place match does not confirm an address, unit inventory, shipping availability, delivered price, or any supplier service area. No ZIP+4 records, street addresses, or coordinates are used by this derivative.