Originally Posted by
goldiemack
I confirmed upgrades for my family and I using RPUs and had my MileagePlus number on the itinerary. I'd now like to credit my flight to my US Air account. Anyone know if I will lose my seat assignments if I do this? I talked to one agent who said no, but was wondering if anyone had experience with this. One of the upgraded segments is 11 hrs, so the seat matters!
To be clear, it is the RPU that drives it. You could have "sponsored" yourself with your UA number, while using your US number. (I have done this many times.)
Had it been and UDU, I have heard of people being downgraded/seat switched when they change their UA number. (I cannot personally say this has happened to me, except being pushed out of E+.)