text: As of June 2016, there are 124 postcode areas, 2,987 postcode districts, 11,192 postcode sectors, and 1,500 post towns. , 55,540 full postcodes in England and Wales contain only one household. Addresses receiving large volumes of mail are each assigned separate "large user" postcodes. But most postcodes are shared by several neighbouring properties, typically covering about 15 addresses.
  Life-cycle of postcodes
  There are also significant numbers of discontinued (terminated) codes. Each month some 2,750 postcodes are created and 2,500 terminated.
  Postcode Address File (PAF)
  The Address Management Unit of Royal Mail maintains an official database of UK postal addresses and postcodes in its Postcode Address File (PAF), which is made available under licence for a fee regulated by Ofcom. The PAF is commercially licensable and is often incorporated in address management software packages. The capabilities of such packages allow most addresses to be constructed solely from the postcode and house number. By including the map references of postcodes in the address database, the postcode can be used to pinpoint a postcode area on a map. PAF is updated daily.
  On its website, Royal Mail publishes summary information about major changes to postcode sectors and postal localities (including post towns). Individual postcodes or postal addresses can be found using Royal Mail's Postcode and Address Finder website, but this is limited to 50 free searches per user per day.