I have a question regarding upgrade awards on star alliance.
Will I be able to upgrade one leg (OSL-BKK) with TG using frequent flyer miles, even if the ticket is an award ticket (bought using frequent flyer miles).
I didn't have enough miles to buy a whole return in business class using ff miles, also, the miles I would want to use on the upgrade are from a different FF program than the one I used to buy the return economy ticket.
If they don't allow me to do so over the phone, is there a possibility they would allow me to do so at the airport IF there are seats available?
(ticket is bought using SK miles, upgrade would be with TK miles)