I can't seem to get a specific answer from either NW or CO so maybe someone here can help.

I'm NW Plat and have been fortunate enough to get upgrades when flying CO but I am booking using my WP number which along with my status appears on CO BP's. So obviously the mileage goes on my Worldperks account.

I want to buildup my OnePass mileage but don't want to loose my Plat upgrade opportunities while doing so.

Can I have it both ways ?

AFAIK, you cannot. And you won't get a status match either, most likely, since NW and CO are both SkyTeam.

Nope. Even though you're Platinum on NW, think of it as your WP number being Platinum. The second you put a OP number in, CO's automated systems will consider you to have whatever status that OP number has.

I have status on both. WP is a better program than OP in my opinion. WP is more generous with other ways of getting more miles, OP has that silly fee for booking rewards inside of 14 days, and there is next to no access to 25K and 45K CO Reward seats even if you're OP Platinum (in my experience). So, you have to pay 50K and 90K, which you can do with WP miles anyway. And all of those Delta 45K first class award seats available in WP don't exist in OP.

My advice is to use the program of whichever airline you fly the most.

On a similar subject...

Can one get a mileage upgrade using WP miles (on a NW flight), but give a OP number for the ticket, in order to get OP miles for the paid ticket?

Any ideas? Thanks

Yes, you can. You will have to call NW after you purchase the CO ticket anyway in order to use NW miles to upgrade, so just purchase the ticket and neter your OnePass number, then call NW with the confirmation number and try to upgrade. You also should determine whether there is mileage upgrade space for NW before purchasing the ticket.

I think he said he's buying a NW ticket and upgrading it with WP miles but wants to put his OP number on the ticket to collect the miles in OP.

This should be easy to do. Buy the ticket on nwa.com. Select the mileage upgrade from the dropdown menu. You will have the chance to put in your OP number (or any other ST carrier). Keep in mind, if you want all the OP EQM's, you have to book the NW flight in fare basis code Q or higher. The nwa.com website allows you to select "Q or higher" from a dropdown menu. Good luck.

This can be done.

I switched from CO Plat to NW Plat a few years ago and got almost all my EUAs as a CO Plat (on both NW and CO metal). Then when I did my OLCI, just replaced my CO OnePass # with my WP #. Kept the upgrade and booked all the miles to my NW account. Not sure if this still works, but used to work in reverse as well...as long as you didn't have a person do the switch for you...the CO system will hold both numbers and show the status of the higher one (or at least it used to do it).

Woops - you're correct.

What happened on your return segments?

I can understand making the switcheroo on the outbound journey after your upgrade has cleared (or not cleared as the case may be), but once you make the switch on the outbound, doesn't it compromise you EUA chances on the return?

According to NW, the EUA's will be processed according to the status of the FF# entered in the reservation. So if you have a CO Platinum and no status in WP, and your CO Platinum is entered in the reservation of the NW ticket, you'll be processed as a CO Platinum, which supposedly equals a NW Platinum.

Perhaps I was unclear. This is the scenario I had envisioned:

It definitely jeopardizes the upgrade. See my comment on this from about 10 hours ago.

Depending on the length of the trip, as soon as I made the outbound and it was posted to my account, I went in online and changed it back. Many did this at the same time CO implemented the 50% EQm...the reason I changed away. Many times, I had already cleared my EUA at the 5-day window, so I didn't need to change it on the shorter trips. Now, miles post to your account typically within a day of completing the trip, so if your upgrade hasn't cleared by that time, I'd log in and put your number back in.

Thanks for all the replies!
I have my OP # in with the NW reservation (therefore, cannot see it when I login to WP).
When I upgrade with miles online, the CO OP number stays in the FF# section. I guess this makes sense because one can upgrade someone else using one's own miles. The person that gets the upgrade can choose which program to accumulate miles.

Thanks for all the replies. I have several CO flights coming so I'll do some experimenting and will follow up in this forum.

Just to make sure I was clear on what I'm trying to accomplish and for additional input this is it:

I fly enough miles to be Plat on one and silver/gold on another.

I wish to retain my NW Plat status. My preference is NW but NW doesn't cover south Texas very well and I have to rely on CO for those routes.

The main reason I want to obtain elite status with CO is that I check two 69.5 lbs. bags and pay $25 for each bag, each way on CO. Obtaining elite status gives me 70 lbs. and will save me $100 per trip.

Even when I achieve silver/gold on CO and satisfy the above I will still losing out on my EUA Plat opportunities unless there's away around it.

I've tried several times to get my Plat status honored on CO for the sake of saving the overweight fee but have failed.

Right now I have a return trip coming up under Plat status but I see no way on the website that I can change FF# myself. OLCI may be a different story.