Originally Posted by
mmack
Flying SFO-LHR, then on a separate ticket flying on BA LHR to EDI. (I miss the UA-BMI alliance)
It's very possible you could have booked this on a single ticket.
Originally Posted by
mmack
We'll arrive in terminal 1..how much time should we allow to get to BA? Is it all Terminal 5?
Given you have a separate ticket, I might allow well more than 2 hours (if doing T1->not T1) as others have suggested depending on your class of service (both for the FastTrack card and for the arrivals lounge

) and passport.