Originally Posted by
Mats
The only time I got stuck was with a mileage bonus. I purchased an instant upgrade ticket, which "booked in to 'P.'" I didn't get a 50 percent mileage bonus, and the agent explained that it was actually an "M" ticket. I needed to dig deeper to figure that part out.
An instant upgrade M fare is fundamentally different from these UPs. The instant upgrade books into PN, not P. You will never get a mileage bonus on that fare (unless your fare code gets changed to full J or F during IRROPS).
It's also fundamentally different in that (a) an M is sold as an economy fare with a possible instant upgrade to J/F, and (b) you can buy an M
regardless whether the upgrade is available. If the instant upgrade is not available, you will book directly into economy. By contrast, the defining characteristic of these UPs is that they
never book into economy at purchase - they are
only offered for sale by UA if the corresponding business or first booking class is available.