postalarea

A postal area is a geographic region defined by a country's postal system to facilitate mail sorting and delivery. It is typically associated with a code or set of letters that identify the area within a national postal network. In some countries, the term postal area is synonymous with the first part of a postcode or ZIP code, while in others it refers more broadly to a group of locales used for routing.

In the United Kingdom, the term is closely tied to the postcode area, which consists of one or two letters that designate a broad geographic region, such as SW for Southwest London or EH for Edinburgh. This area code is followed by digits and sometimes additional letters to form districts, sectors, and units, all of which help sort mail before it reaches the delivery route.

Other countries use similar concepts under different names. In Canada, the first letter of the postal code indicates a broad region within the country. In the United States, ZIP codes perform a related function for routing mail, with the initial digits designating a sectional center facility region, though the term postal area is not commonly used in practice there. Across systems, postal areas may cross administrative boundaries and can evolve over time as routing needs change.

Postal areas support address standardization, efficient sorting, and delivery routing. They are also used in logistics planning and geographic analyses, helping to estimate distribution patterns and inform service coverage.