The Universal Suppression Service (USS) is a file made up of deceased and gone-away records collated from various sources by the Royal Mail. The main source is from The Royal Mail themselves, from mail redirections and returned mail. Other sources include selected companies who contribute their returned mail to the USS file and who let The Royal Mail know of other changes to addresses that customers have informed them of. Some of the sources are verified and others are not. It is only the records that include persons who have paid The Royal Mail to redirect their post that can be 100% verified.

If a person moves house and redirect their mail they are added to The Royal Mail’s Redirect file. If they agree to share this information with third parties they are added to the National Change of Address File (NCOA) and to the USS file. If they do not let third parties know their new address then they are only added to the USS file. The file contains over 12 million records and is updated monthly.