The problem with Fast Track on arrival into Heathrow is that it is only valid for citizens from outside the UK / EU as clearly stated on both the Heathrow Airport https://www.heathrow.com/airport-gui...ces/fast-track and British Airways websites. If you are an EU or UK citizen they turn you back -even if you have a fast track card - and you have to go to back of queue for UK / EU passport holders or head for the electronic passport gates.