Originally Posted by heckler
Banking is a technique to book a future flight which is after the date of expiration of the PMU. So i'd book a flight for next summer, on a fare which is both cheap and no change fee/refundable. Therefore the PMU is "stored" so to speak for use later - whether I actually use it for the flight I booked, or if I change the ticket to another flight i'd like to take - say Paris. If i changed, the value of the existing ticket would be applied to the Paris trip, and then the PMU would be moved over. Banking PMUs is probably more useful for those who are doing international segments, since Skymiles now has the unlimited domestic upgrade system.
In short: It's basically a way to keep a PMU in play longer - if you have the cash and forthought to book travel into the next year.
OK, so it is what I came to think of it on my own. I have never used this technique yet, but on the other hand I have never run out of PMUs. I also have 5 PMUs left this year and am using 2 for thanksgiving on domestic leg only because I do not want to play the lottery on flights which are going to be very full and full of other PMs. But since I am getting 8 PMUs next year, I do not think I need to bank the remaining 3. I probably will make reservations in February for an actual int'l trip in March, so I will only lose 1 PMU.
Pray tell, what is the kind of Y/B/M refundable fares have you been able to come up with in the past?
Did you try travelocity's fare tool?