Originally Posted by
BlueMilk
YMMV.
When I've tried this within 2 hours of departure, I've been unable to find an agent capable of the feat. Good news is the upgrade has always cleared at the gate. (Travelling on a domestic M flight pass.)
It is AC1151 YYZ-YYZ and was J1 R1 so I rushed to the SE check in desk and he said he cant do it and sent me over to the concierge and she took care of it for me.
Plus my original flight AC133 was full so they didnt even charge me same day change!
Good times!