Current geographic source
The current release uses the United States and Australia files from the GeoNames postal-code export. The build pipelines download US.zip and AU.zip. The US dataset keeps the 50 states; the Australia dataset keeps all 8 states and territories.
Fields and cleaning
The US browser dataset contains city, state, two-letter state code, five-digit ZIP code and county. The Australia dataset contains locality, state or territory, official abbreviation and four-digit postcode. Incomplete records and exact duplicates are removed, whitespace is normalized, and coordinates and unused source fields are omitted.
A result selects one complete source row, so related geographic fields are not mixed independently. ZIP codes and postcodes stay as strings so leading zeroes are preserved.
Synthetic street data
House numbers and street lines are generated for testing and are not selected from a resident-address directory.
A generated combination may coincidentally resemble an existing location. The finished result is not represented as nonexistent, verified by a postal authority or deliverable.
Limitations
US ZIP geography can cross county boundaries. The displayed county belongs to the selected GeoNames place row and is not a legal, property, tax, emergency or USPS-grade boundary decision. Australian locality and postcode records are not the licensed Australia Post commercial address database. GeoNames data is provided as-is and may be incomplete or outdated.
License and attribution
Geographic data includes GeoNames data under the Creative Commons Attribution 4.0 International license. See the GeoNames postal-code readme for source field definitions.