Postcode
The term used in the United Kingdom, Australia, and several other countries for their alphanumeric or numeric postal code system.
In the United Kingdom, the postcode system was phased in between 1959 and 1974 and uses an alphanumeric format divided into an outward code (area + district) and an inward code (sector + unit). A full UK postcode such as EC1A 1BB identifies a group of roughly 15 addresses. Royal Mail manages approximately 1.8 million postcodes across the UK.
Australia uses a simpler 4-digit numeric postcode system introduced in 1967 by Australia Post. The first digit indicates the state or territory: 2 for New South Wales, 3 for Victoria, 4 for Queensland, and so on. Unlike UK postcodes, Australian postcodes map to broader geographic areas.
The word 'postcode' is also the standard term in the Netherlands (where it is written as one word: 'postcode,' using a 4-digit + 2-letter format like 1012 AB), Singapore (6 digits), and Malta (3 letters + 4 digits).