A postal code is a series of letters and/or digits appended to a postal address for the purpose of sorting mail.
Germany was the world's first country with a postal code system in the early 1960s. The United States followed a couple of years later.
The vast majority of the world's national postal services have postal code systems. A few do not: Ireland (with the exception of Dublin) and Hong Kong, for example, do not have postal codes1, while New Zealand's post code system is only used for the presorting of mail in bulk, not for addressing individual items.
Postal services often have their own distinctive formats and placement rules for postal codes. (Service areas, as a rule, are defined by national borders.) In most English-speaking countries, the postal code goes after the name of the city or town, whereas in most continental European countries it goes before it and is sometimes prefixed with a country code (ISO 3166-1 alpha-2).
Although postal codes are usually assigned to geographical areas, sometimes this is not the case: special codes may be assigned to institutions with large volumes of post, such as government agencies and large commercial companies. One example is the French Cedex system.
Alphanumeric postal codes
Most postal codes are numeric. The few using alphanumeric postal code systems (with letters and digits) are:
Postal zone numbers
Before postal codes as described here were used, large cities were often divided into postal zones (or postal districts), usually numbered from 1 up within each city. The newer postal code systems often incorporate the old zone numbers, as with London postal district numbers, for example. Dublin, Ireland still uses postal district numbers, as postal codes are not used in the country at all. (An Post relies on OCR analysis of the entire address instead.) In New Zealand, Auckland, Wellington and Christchurch were also subdivided into postal zones, but these have fallen into disuse.
See also
- Universal Postal Union (UPU)
- List of postal codes — for all countries (shows each country system's respective syntax only)
- Lists of postal codes — index to full postal code lists for each country
- Postcode — article about British postcodes
- ZIP code — article about U.S. postcodes
- Canadian postal code
- Category:Lists of postal codes
External links
- UPU files for every country in PDF
- Formats of all countries' postal codes
- German postal codes in German language
- French postal codes in French language
- Canadian postal codes
- International zip codes
Footnote
1 Irish postal district/zone numbers (see above) are used for Dublin only. Confusingly, these postal zone numbers are sometimes also called postal codes—which could be seen as technically incorrect. In addition, at the time of writing Ireland is currently in the processing of creating a Postcode system for the state.