I booked SEA-SFO-LAX all on CO flight numbers on continental.com, on UA metal. (I wanted to be able to do a 24-hour same day confirmed change with CO's superior rules.)

I supplied my UA Mileage Plus Number, only, to continental.com.

When I looked at the reservation on united.com it showed that my frequent-flyer numbers were:
CO: (CO#)
UA: (UA#)

I didn't think much of it.

Now that I've checked in, I see that my boarding passes have a giant "STAR G" on them and the only frequent flyer number listed is my CO one.

That would explain why my upgrades didn't clear (and now the F cabins are full).

Lesson learned -- always call UA on codeshares to double-check FF#.

Hilariously, even after I change my FF# to the United number, cancel check-in, and check-in again, the boarding pass that united.com prints just says "CO*G" and lists my CO#.

Why I thought I would be on the upgrade list as a 1K: "My Reservations" shows my UA MP number (which I entered on continental.com as my only FF# associated with this reservation) on top of my CO OP number.

http://i.imgur.com/GaENH.png

Notice that there's no place to edit the FF# here because it's a CO ticket. Here's what my traveler info looks like on continental.com for this reservation - my CO FF# is attached nowhere and never was.

http://i.imgur.com/VhI2c.png

So imagine my confusion when I OLCI to see "STAR G" and "CO*G" and my CO number only, on my boarding pass.

What happens after a little extra prodding: I can get united.com to claim that my FF# is my UA MP#. But even then, Easy Check In spits out this awesome view showing, on a single printed page, two different frequent flyer numbers and statuses for two different segments:

http://i.imgur.com/82rSt.png

Edit: just for fun, I called both UA and CO.

UA: "I see both your United and your Continental numbers here. We can't change anything about this reservation."
CO: "I see only your United number. No idea why United sees your OnePass number."
united.com support: "I see that both numbers are on there. Would you like me to fix it? OK, fixed."

I love Web support. Don't ever change, guys.

Had a very similar problem; despite 2 phone calls to UA 1K line and 1.5 hours on hold (with some very nice people) it was not fixed;
Once I got to the airport it was fixed and I was upgraded right there.
I was upgraded because first was not full.
So from now on, I buy the ticket on the site that I will fly more segments or have the segments that I want upgraded the most.
It is not helping my trek towards the million mile mark unless the new UA mileage plus will add up the CO and UA lifetime miles.

Followup: I traveled in coach on both segments. But I was #7 on the upgrade list for the first A319 segment, so I'm not sure that would've cleared anyway.

I had a similar thing happen recently -- the itinerary had three segments and Mr. Easy Chicken actually only printed the first boarding pass! (Even though it was happy to find the reservation via either MP or OP# lookup.) When I talked to the agent, the other two boarding passes came out with my CO #. She changed it manually to MP on my request, but mentioned that the discrepancy was probably the reason the kiosk didn't print them all.

In my case, I think the CO number did autopopulate originally when I booked on co.com, and then I changed it later on CO's site, which caused it to push over to the UA reservation, at which point they both showed up on the UA site. My best guess is that there's something wrong with the sync process, such that it only updates your first segment with the number as modified by CO, rather than all of them. .bomb then seems to compound the confusion by showing both numbers indiscriminately at the bottom of the reservation. It would really be better if it would show them seg-by-seg, like it does for seats. (But this will probably go away soon anyway since SHARES appears to store the number at the reservation level.)

I have no idea why any of this would happen if you /never/ entered your OP # to begin with, though. Were you logged into co.com when you made the purchase? It could be that that alone stealthily inserts your OP # somewhere in the PNR...

Changing FF# on Easy Check-in
 

Since I have been flying on mixed itineraries where UA is outbound, CO is return I have put my OnePass # on the CO segments and put the MileagePlus # on the UA segments. Which in theory works, but YMMV. For some reason the UA PNR has picked up both although when I went to check-in it displayed MileagePlus on both boarding passes.

In the instance that I cleared both upgrades in advance, I went to the Easy-Check in and changed my MileagePlus # to OnePass. On segment 1, it will spit out a boarding pass with the OnePass but on segment 2 the boarding pass will show no status, nothing. I went to the agent and they manually entered it and printed a new boarding pass with OnePass. Imagine my surprise when I look at my statement a couple of days later and the mileage was credited to UA.

I don't like having to use a UA number for UA flights and a CO number for CO flights....we are all going to be dumped into one program so while it may seem beneficial now for clearing on each carriers metal by using the respective carriers FF Elite status, its just a pain in the butt.

You know that CO's rules are now UA's rules on SDC. Have been for a while now.

Is that right? I don't see it reflected on ual.com, though. Can you provide a link for future reference? TIA.

LAX

Not according to UA.

http://www.united.com/page/article/1,,52142,00.html

I had this exact issue last week on SFO-IAH-FLL. Booked through CO, all CO flight numbers, CO Plat # on res, but the SFO-IAH was on UA metal. There was plenty of upgrade room on SFO-IAH, but my upgrade did not clear in advance (IAH-FLL did). I asked at the RCC the night before and they said that I was never on the list and they do not know why. They manually put me on the upgrade list and I cleared at the gate.

For some reason, these mixed CO/UA metal itineraries are not upgrading properly.

All my mixed UA/CO are upgrading just fine :confused:

ditto here.

FWIW, the same day change rule is based on operating carrier, not marketing carrier.

100% false and wrong. Do a search on the threads and you'll find a very lengthy thread about it.

CO: 24 hours, same fare class in the same cabin
UA: 3 hours, any fare class in the same cabin (although some still report you need H class to be available, not Y).

-RM

My friend ran into a similar problem. He's leaving tonight on HNL-LAX-LAS.

HNL-LAX is CO and LAX-LAS is UA. As a CO gold, he told me he was getting UDU'd 100% of the time from HNL-LAX.

He was already UDU'd from LAX-LAS a few days ago.

This time, he went to check in 24 hours before the flight and it he couldn't check in. He called CO and they said although his reservation is still in the system, it's frozen and there's nothing they can do about it. He was told to show up at the airport and take care of it there.

Oh, and he was also told that because of this, there's no chance of a UDU for the HNL-LAX segment.

I've never heard of such a thing happening and now I'm really reluctant to book a mixed metal flight.

Thoughts?

Finally, what is the process for upgrading a mixed itin? If I use a CR-1, can I do it on-line?

Are you changing you FF #'s?
 

What FF # are you using and how, would like some help on mixed carriers and UDU.. Thanks and Safe Travels