Originally Posted by
c5marine
Trying to use points to upgrade for a flight Friday night (I am silver). Told me I was wait listed. There are still like 8 unsold first class seats.....how long does it take for it to clear? Would have thought if I "bought" them with miles I would get it instantly....and the miles were deducted from my account..
Doesn't work that way, unless they have available inventory
in the relevant bucket. They don't
have to offer a single seat, if they choose not to, and instead sell whatever they can for cash. The only time they
should automatically clear your seat is when your flight has that seat in "R" fare class available.
So the booking engine can show F9, implying that 9 or more F seats are available... and all that means is that they're available
for sale. The seatmap can show F being wide-open, and that still doesn't mean you'll get a seat using miles. Especially if you're not an elite on UA.
Details regarding fare classes can be found
here.