Originally Posted by
KevinM2
I am going to purchase a GLA-LHR return flight for my wife and myself (I didn't want to purchase it until I was sure I could do this first), and when I get to GLA, ask the check-in person to check our bags all the way through to SFO.
Would that be OK?
Yes, that's possible. Ensure you have enough time to connect at LHR as if you're GLA flight is late into LHR, BA don't have to accommodate you on another flight since you're on separate bookings (though they might).