Originally Posted by fly747first
I think you can change your frequent flyer number on the day of departure. On the few times I have used confirmed regional upgrades for flights on United (these days many more than US Airways', I love the Q-UP fares), I have been able to change my frequent flyer number to credit the miles to US Airways at the airport. Please do not waste 20,000 miles to upgrade to First Class on a US Airways domestic flight, all you will be getting is a bigger seat.
As one is mostly flying United metal for US Dividend Miles, save your boarding stubs. Even with my US CHM Preferred Status and USAirways # on the boarding pass, the mileage and flight credit still went to my United Premier Exec account on one I changed at the gate. Am awaiting word on whether US will give me credit.
Outoftown