Editing Postcodes in the United Kingdom (section)

=== Postcode use ===
Postcodes have been adopted for a wide range of purposes in addition to aiding the sorting of mail: for calculating insurance premiums, designating destinations in [[route planning software]] and as the lowest level of aggregation in [[census]] enumeration. The boundaries of each postcode unit and within these the full address data of currently about 29&nbsp;million addresses (delivery points) are stored, maintained and periodically updated in the [[Postcode Address File]] database.<ref name=guide/>

Theoretically, deliveries can reach their destination using the house number (or name if the house has no number) and postcode alone; however, this is against Royal Mail guidelines, which request the use of a full address.<ref>{{Cite web|url=https://personal.help.royalmail.com/app/answers/detail/a_id/81/~/how-to-address-your-mail-(clear-addressing)|title=How to address mail clearly, guide to clear letter addressing|website=personal.help.royalmail.com}}</ref>