Postal Code
A series of letters, digits, or both used by postal services worldwide to sort and deliver mail to specific geographic areas.
Postal codes are the generic international term for codes that postal services use to route and sort mail. Different countries use different formats and local names: ZIP Code (United States), Postcode (United Kingdom, Australia, Netherlands), PLZ (Postleitzahl, Germany and Austria), Code Postal (France and Belgium), PIN Code (India), and CEP (Brazil). Formats range from purely numeric (United States: 5 digits, Japan: 7 digits) to alphanumeric (United Kingdom: outward + inward codes like SW1A 1AA, Canada: 6 characters alternating letters and digits).
The concept of dividing a country into postal zones dates to the early 20th century. Ukraine introduced a numeric system in 1932, and Germany rolled out a two-digit Postleitzahl in 1941 to speed military and civilian mail during wartime. The modern era of machine-readable postal codes began in the 1960s, with the United States, United Kingdom, and other nations adopting standardized systems.
Today, nearly every country and territory has a postal code system. The Universal Postal Union (UPU) maintains a reference database of national postal code formats, though each country's postal authority manages its own assignments.