Sources & methodology

Where our postal code data comes from

Every postal code, locality and count on this site comes from one source dataset, last updated on 1 September 2026.

What the data covers

The site has 209 country pages, built from 185,131 rows. Each row is one locality with its postal code (where it has one), its administrative divisions (region, department and, where they exist, finer levels), coordinates and time zone, as far as the source provides them.

These pages are built from a reduced export of the database. The row count at the top of each country page ("47,892 rows" for France) is our full database's count for that country; the codes listed and counted on the pages themselves are those of the published rows.

Only standard delivery codes are included. Business codes, CEDEX codes and PO box codes are left out of these pages.

Our full database covers 247 countries and territories. 26 territories in the dataset have no page here, because their data does not yet produce a usable page: Åland Islands, American Samoa, Anguilla, British Indian Ocean Territory, British Virgin Islands, Cayman Islands, Christmas Island, Cocos (Keeling) Islands, Cook Islands, Curaçao, Falkland Islands, Faroe Islands, French Guiana, French Polynesia, Gibraltar, Guadeloupe, Guam, Montserrat, New Caledonia, Niue, Norfolk Island, Saint Martin, Saint Pierre and Miquelon, Sint Maarten, South Georgia and the South Sandwich Islands, Svalbard and Jan Mayen.

Where it comes from

Postal data. The rows come from an export of our postal database: one file describing each country's administrative levels, one with a row per postal code, and one with additional rows for the cities the source lists separately (for example by district), which become this site's city pages.

Postal code formats. Each country's format pattern, example codes, postal authority and address component order come from our postal format reference. 139 country pages have a recorded format and 120 an address order. When an example code in the reference doesn't match its own pattern, it is replaced with a real code from the dataset. A country with nothing on record shows nothing; nothing is filled in by guesswork. The postal code format guide lists them all.

How often it is updated

These pages show the dataset as exported on 1 September 2026. When a new export is ingested, every page is rebuilt from it, and the date shown under each page title ("This page shows data as of …") changes with it. That date is the date of the data, not the date the site was last published.

How the pages are built

Every country, region, department and city page is generated from the rows for that place, and from nothing else. The answer under each page title — the codes, their range and their count — is computed from all of the place's rows. The tables show up to 50 of them: on country and region pages, a random sample spread across the regions; on department and city pages, the place's own rows. The complete listings are part of the full database.

Descriptions are written from the same data: a place's towns, its subdivisions, its postal prefixes. National facts such as the format, the postal authority and the address layout appear once, on the country page.

What "no postal-code system" means

Some countries don't use postal codes. A country is shown as having no postal-code system when every row in the dataset for it has an empty postal code and a manual review confirmed it. Its pages list localities and their administrative divisions instead of codes. Countries where the review is still open are not marked this way.

The 50 countries currently shown with no postal-code system: