Originally Posted by
JJeffrey
If you don't check bags there's virtually no difference in the connecting process on separate tickets vs. a single ticket. Check in with BA online beforehand so you already have your boarding pass, when you arrive you just proceed to flight connections like usual, take the bus to T5, and proceed through the BP check and security and to the gate/lounge.
Indeed, and even if you can't/don't check in online there are dedicated connection check-in (ticketing) desks on the right wall as you face T5 passport control, who can sort out a boarding pass if needed.