Originally Posted by
Lucanesque
OK, I think I know what's happening - if you do a search on
google flights or Matrix, you will get the £973 fare, clicking through to the BA site tells me it's selling class T. If you do the same on BA's site, with an UUA as part of the booking it comes out as £1,503 + 60,000 Avios. What I can't tell is what selling class the latter is, although it's clearly different.
What you need someone more expert than me to say is whether or not a T fare can be UUA - if the answer is yes, and assuming there is still the U availability when you come to book, then I'd book the £973 fare and immediately upgrade once ticketed.
This looks like a problem with ex-LHR DIFs, yet again.
The cheaper T class fare, if bookable on its own on ba.com, will be UuAable. In any event, it's zero risk - if you phone after booking and it turns out that it's not UuAable for some odd reason, then you can do a cooling-off cancellation.
Any similar problem seen on ex-EU itineraries will almost certainly be attributable to ba.com trying to UuA all four sectors of the journey instead of just the two long-hauls. Again, it is possible to UuA the two long-haul sectors alone, just not on ba.com.