UK Postcodes

What they are and how to find them.

Postcode Structure

UK postcodes are alphanumeric and between five and eight characters long (including a single space separating the outward and inward parts of the code), e.g. the code for the House of Commons is SW1A 0AA.

The 'Outward' part of the postcode denotes the postal district - for example RH for the Redhill area, and then the following number distinguishes the post town - broadly speaking the Delivery Office which services the local area. So RH1 is Redhill itself, RH10 is Crawley. With larger towns there may be more than 1 number in the outward section - Crawley includes RH10 and RH11. The 'Inward' part denotes particular parts of the town / Delivery Office area, with the first part - the number - being a sector, and the final two letters denoting a group of houses within that area.

For more see Wikipedia.

To Find a Postcode

  1. Go to
  2. Enter the Building Number or Building Name in the fields provided.
  3. Enter the Street name.
  4. The previous two values are often sufficient but to reduce the number of matches you can enter the Town name as well.
  5. Press the "Find Postcode" button.
  6. All matching addresses and postcodes are listed. Click on one to see a map showing its location.

To Find an Address from a Postcode

  1. Go to
  2. Click on the "Find an address" tab.
  3. Enter the Postcode in the field provided.
  4. Press the "Find an Address" button.
  5. The address is displayed along with a map showing its location.