Originally Posted by
KARFA
UuA should be fine subject to the booking ticking the boxes, you will have to phone to do it - see
https://www.flyertalk.com/forum/30609139-post6.html under Upgrading Using Avios
POUGs will pretty much never be offered for a TA booking.
AUPs may be available but you will have to wait and ask at the airport.
I
believe UUA of a TA booking automatically brings the ticket under BA's control even if before T-24 (at least this is what I have been told when I have done it).
If that's the case then your TA would now no longer be able to do anything with the ticket, which may/may not be an issue for you/your work.