So this is a weird question, but it has signifigance to me for a few months here until I move to Long Island. I am CO Gold for the upcoming FF year, and still have a bunch of flights on CO and NW while I am here in SEA.

I want to collect EQM in Delta on these flights so I can hit Gold/Plat with them going forward, as they'll be my new program. (Ugh, I miss CO already just typing that.) I want to know if it's possible to use my CO status to get on the upgrade list for an itinerary, but collect my miles on SkyMiles? Either by showing status at the gate, or putting the itinerary on the CO# until check-in and then changing it over to the SkyMiles# ...?

Generally no. Once you switch your FF program the upgrade is supposed to go away. I don't know of anyone who's tried lately, but that's the way it is supposed to happen.

I believe (although I have never tried it myself) that you will lose your EUA if you change your frequent flyer number after having received an upgrade. NW, however, allows one to change frequent flyer numbers and keep an elite upgrade.

Why are you changing to DL and not continue to accrue OnePass miles?

I'm guessing since the poster is moving to Long Island they will be flying out of JFK instead of EWR, making DL a better choice for accruing miles.

As much as I would love to, I will be locating fairly far East on Long Island, and EWR will just never be a good option unless I am flying Int'l or to smaller EC markets where DL or someone else doesn't fly. My flying will mostly be JFK/LGA to IAD/DCA it seems, and occasionally JFK-SEA. (I work for Microsoft, so regular trips to HQ.)

If I am going to be in DL metal so much, it makes more sense to have status with them than with CO, even though I really would rather stick with CO.

Don't worry. You will not be upgraded on the transcon flights anyway and who cares about being upgraded on the short haul ones?

What you could be doing though is...
1) open a new accound with UA
2) Match this account with your CO to get status
3) Match your DL account with your newly created UA account

Or just ask DL to match you. I did last week and I mailed in my info and was told no problem.

Ciao,
FH

Apparently you can have much greater upgrade success flying transcon on DL as a Gold than you can on CO. I take it they don't offer Y-up, low Z-fares, and other incentives to fill the front cabin with revenue well before the flight. I got upgraded on SEA-EWR-SEA 3 times this year (as a silver) in 16 tries. Thanksgiving Day, Christmas Day, New Years Eve.

I did, and they did! So I am DL Gold now, which helps on my DL segments...but DL doesn't help me much while I am still SEA-based. It will matter more once I move. If I can use my hard-earned CO to get me upgrades for the next 6 weeks (I have 12000 miles before the end of this month...geez) until I move, great.

I am trying it right now on an NL itin. I have a B-fare this sunday for SEA-MSP-YYZ, which should put me high up the list for upgrades. If I get one, I'll switch back to my SkyMiles # and see if they take it away from me. I'll report back here with the results.