Originally Posted by
cxfan1960
OP did not mention about a Y booking in Post #1 (that you quoted). He was merely saying about letting the K booking lapse. You read his mind
.
Yes, at least in the past, he can decouple the upgrade from the underlying booking, but the change fee can be substantial if the original booking class is not available for the rebooking. He can also try to change flight without additional cost at the airport on the departure day. It is risky.
that's what i (kind of) am doing right now, so i read his mind
(the hint line was :re-book again before 20 Mar, can I still get the upgrade?)
but i dont know, i never managed to get change fee waived on day of travel (from LHR), AND cheaper ticket + change fee is sometimes still cheaper. (and i'd thought original booking class not available does not actually matter cuz u're after a U-class seat anyway, but i may be corrected.)