Originally Posted by
nova08
With regards to miles for upgrades does the carrier you purchase from or the operating carrier matter?
Not for flights on CO metal. It does for flights on UA metal.
Originally Posted by
nova08
From the above I take it that even though he purchased from UA because its operated by CO he can use miles to upgrade on any fare class, not just B and above?
So long as it is CO miles, yes.
Originally Posted by
nova08
Edit: A few things I didn't see mentioned are whether he's trying to use UA miles or CO miles and if he's matched to a CO Plat
The match doesn't matter but the miles used do; I, too, skipped over that part. Assuming CO miles it would be a trivial task to get the upgrade. Assuming UA miles it would have been impossible (though now UA miles can easily become CO miles so that does make it easier).