Originally Posted by
sbm12
This isn't particularly helpful because one would be buying the ticket on a different carrier and then upgrading.
I'm quite surprised to hear that CO cannot check the upgrade options until the flight is ticketed. I'd try again and get a different agent to look at it.
FWIW, UA told me the same thing when I was trying to use my UA miles to upgrade an SQ itinerary. According to UA, they need a confirmed ticket, and then they can search for upgrade availability. I didn't think much of it at the time and just thought it was SQ being picky.