Originally Posted by
tobikosan
GGUs are Alaska Gold Guest Upgrades?
Yes.
Originally Posted by
tobikosan
If so is there a way to use them to upgrade international partner segments?
No, they are only good on Alaska flights. There is really no incentive for BA, JL or EK to allow AS loyalty program members upgrade for free (it would in fact be a DISincentive to credit to their program). AS is partners with these airlines but not in alliance with them, so there isn't even that small reason to allow it.