How Postal Codes Work Around the World
Postal code structure
A postal code is a short string used by a national postal service to sort and route mail. Formats vary by country: the United States uses five-digit ZIP codes, Canada uses letter-number pairs, and the United Kingdom uses alphanumeric postcode districts.
The structure usually encodes a region, district, and delivery area rather than a single address.
Formats and examples
Country-level reference pages show the format description, a validation pattern, and example codes from a public dataset. For example, the US format is NNNNN[-NNNN] and Canada is A0A 0A0.
Examples are structural valid codes, not records for specific real addresses.
What this reference covers
The current version publishes country-level postal formats rather than a full worldwide database of individual postcodes. The architecture keeps room for detailed datasets later.
Each postal page links back to its country page so the format can be understood alongside the rest of the country reference.