Originally Posted by
whmere
Just wanted to point out that while this is a great use of miles, it makes availability even harder to get. You need open seats on both the l/h and s/h segments in order to score your upgrade. Availability on just the l/h is both the one that matters, and more available.
It is even more complex. When I tried to upgrade a HEL-LHR-YYC (and return) ticket from WT+ it turned out there was availability on 3 of the 4 segments. This resulted in it being possible to upgrade those 3 segments (either that or nothing), however the miles amount needed was 3 times that for a regular one-way MFU from WT+ to CW
I might have accepted that if one of the HEL-LHR legs weren't available, but it was one of the LHR-YYC legs. So BAEC charged me 48750 miles to upgrade one long-haul leg to CW, and one short-haul leg (as I would not have used the last short-haul flight to HEL).... Would I have started in London, the cost would have been 12500 for the one-way MFU. And BAEC charged me more miles for a 3-segment upgrade as they would have for a 4-segment upgrade (32500)....
Somehow when not all legs of a complex WT+ itinerary can be upgraded, you must upgrade all legs available for upgrade, and per leg the cost will be the one-way WT+ to CW/CE cost for the entire trip (or something similar)
Only exception I guess is when only the 2 outbound or inbound sectors are available for upgrade, which would simply result in half the miles for the return upgrade.