Originally Posted by
UAflyerwhoflystomuch
Might be off topic, but I booked a ZRH-SFO on LX in April in J (cash) as UA doesn't fly direct then and I was wondering if there was any way I could A) use miles to waitlist to F B) pay cash to confirm a F seat.
Booking classes J, C and D are upgradable with miles. You need a native LX flight number to get any kind of UG through, so if on a UA ticket on a UA codeshare you need to call to get it converted; on an LX ticket, no problem. You cannot WL. 'Upgrades available' with Swiss is like winning the lottery, it is very rare. Haven't see many reports of that lately, but in theory this still works. It upgrades into a sub-set of A that is not publicly disclosed.
On a UA ticket you can buy a cash upgrade (also needs a native LX flight number), but you cannot 'bid' for upgrades. I have only seen that available for Z or higher. On LX ticket you can also 'bid' for an upgrade.