Originally Posted by
Kiwi Flyer
UA Mileage Plus SWUs can be used to upgrade.
- This upgrade may be used on a standby basis, subject to availability, on the day of travel on any eligible LH flight.
- Valid in all booking classes except when booked in LH booking classes X, I, O, R, N, W and E.
- This upgrade requires a 14-day advanced notification to MP in order to print and mail the certificate for presentation to LH on the day of departure.
Update: UA SWUs in paper from for LH are not valid on X,I,R,N,E,S,W,ID, AD and IP Fares. Additionally not valid on intra europe flights on L and T fares.