Originally Posted by
sdix
I am a UK/US duel citizen living in the US
My APIS info is my US passport.
However when flying to the UK (or anywhere outside of the US) I present my UK passport at check in with no issue. On the return I present my US Passport at check in again, with no issue.
Same here. I usually put my US passport into the booking, and I present it at check in when I'm heading from the US to the UK. I'll use my UK passport at the gate when boarding. I use the UK passport on arrival at the E-gates at LHR with no issue. Then heading home, I use my US passport at check-in/gate