Recently, I status matched to CO. I have lots of US flying over the next few months and that's why. Tomorrow, my mom and I are flying YYC-SFO-PSP on AC/UA. The AC flight was better-timed so that's why we fly AC. 2 days ago, I called UA to add my CO number. The number was added and the AC number removed. Great! Today, 3:55, check-in. I want to use 2 extra SSWUs. I wasn't expecting the "Upgrade Certificate" grey button to come up, but it did. I click, check the names, and apply. Blah blah blah, all the US gov. info filled out, and then the boarding passes pop up. First flight - AC*SE. Second flight - CO*G. Peculiar, huh?!