Originally Posted by
Kernow
For searchable reference...
It is not possible to apply the GUF1 voucher to the booking via a TA as the itinerary has non BA operated segments in it. I can however apply the GUF1 at a later stage via BA direct if redemption availability opens up in the F cabin for the legs or I use a GGL Joker to force the availability. (Experts please correct me if I'm wrong!)
Yes that correct, and it's the current position - even includes the recent change which allows you to apply the GUF for a TA booking by calling BA - more information in the GUF guide too
BA Gold Upgrade Voucher Discussion and Wiki Thread