How do I find a postcode?

How do you find a postcode in the U.K.? With our Postcode Finder, simply type in the partial details you have and soon you’ll be on your way to finding the complete postcode/address.

Our UK postcode finding tool can find you the full address and postcode, even if you only know the house number/name with a postcode, or if you only know the street name and town.

What is a postcode?

Postal codes used in the United Kingdom are known simply as postcodes. They are alphanumeric and were adopted nationally between 11 October 1959 and 1974, having been devised by the GPO (Royal Mail). A full postcode is known as a “postcode unit” and designates an area with a number of addresses or a single major delivery point.

Why we need a postcode?

Postcodes have been adopted for a wide range of purposes in addition to aiding the sorting of the 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 million addresses are stored, maintained and periodically updated in the Postcode Address File database.

How postcodes work

Postcodes are made up of a group of between 5 and 7 letters and numbers that identify a group of houses or addresses. Each postcode has two parts, an Outward and Inward code, separated by a space. Each full Postcode contains an average of 15 delivery points and each postal delivery takes place in two stages.

When a letter is collected it is routed to the main sorting office identified within the first part of the Postcode, the outward Code. The local sorting office uses the second part of the Postcode, the Inward Code, to direct a letter right down to the individual postman’s walk. Postcodes operate at four levels. Take, for example, the Postcode B3 2BJ.