Originally Posted by
Fishbait
Thanks, I was confused. I thought that only M was capacity-controlled - my bad. So, to do the upgrade online, where should I look? At T-26, there was a link on the flight to upgrade, but for $99. Where would I see the button for the B-up (or Y-up or M-up for that matter)?
When you pull up the reservation there will be a link to Upgrade the flight. IIRC it's near the top of the reservation, along with "Export to Outlook" etc., although the layout may have changed. It shouldn't be difficult to find. If the appropriate inventory is available, then there will be no charge to upgrade. If the appropriate inventory is not available, it seems CO will let you buy up to the appropriate inventory. This could be a full Y fare (which allows last-seat upgrade availability), or a "D" fare (which is often less expensive than full Y).