US ZIP Code Lookup
Enter a United States postal code to check its format, view area-level sample data, and generate a fictional test address for that area.
94103 Synthetic test address for this area
6738 Hill Rd San Francisco CA 94103 United States
United States postal code format notes
US ZIP Codes use five digits, with an optional ZIP+4 suffix. A ZIP Code alone does not identify one street address.
Can a postal code show a specific address?
Usually no. A postal code typically identifies a postal area, locality, or delivery range. It should not be presented as a specific street and house number without licensed address data.
Postal area data source
GeoNames · Imported: 2026-06-29 · 41,490 area records
- GeoNames postal code data — GeoNames · Creative Commons Attribution
United States postal code lookup FAQ
Can a US ZIP Code show a specific street address?
Usually no. A US ZIP Code typically identifies a postal area, locality, or administrative region. It should not be treated as a specific street and house number.
Is this postal lookup official delivery verification?
No. This tool uses GeoNames area-level postal data and local samples for format learning, QA, and test data. It does not guarantee deliverability.
Why can a valid postal code return no area result?
Format validation only checks the visible structure. Area results depend on the current dataset coverage; unmatched values are shown as format-only results.
Can I generate a test address from a postal lookup result?
Yes. When an area-level match is found, the page can generate a fictional test address for forms, imports, and development workflows. It is not a real address claim.