Fast Track Immigration (arriving at LHR) is for First and Business class pax with invitation envelopes passed out during flight. (And also nonrevs and friends of FAs who get the invitations on board also.)

"Fast Track" security (departing LHR after checkin at the counter) is for Premium pax and also available to "elites" who can get the sticker placed on their boarding passes, on request if the agent forgets.

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