Mail identification

If mail finds its way into the "wrong" operator's network, it is crucial that the correct operator can quickly and easily be identified. That's why licensed mail (any letter weighing less than 350g and costing less than £1 to post) has in its top right-hand corner a unique three-digit code to:

  • identify the operator handling that piece of mail;
  • show that it is subject to the common operational procedures code, and
  • enable mail that has entered the "wrong" system to be re-routed effectively.

This system came into force on 1 January 2006, when the UK mail market was opened to full competition.

The mail identification code, or code identifier, will not appear on letters carried by Royal Mail - including mail handled under access agreements - as this mail can easily be identified as such. (Access agreements allow mail users and licensed postal operators to use Royal Mail's facilities.)