Originally Posted by
iwillflytheworld
For those who asked, I'm keeping both reservations because I don't know on which date I will be finally able to travel on the outbound, but the return is fixed. I'm not planning to fly both itineraries; as soon as I know which date works better I will cancel the other reservation.
Assuming LH or UA doesn't cancel it for you first. I know UA has a system to check for duplicate bookings. I'm not sure if LH has one, but I would assume so. I think there is less of a chance of the system catching it, because both tickets are issued, but I would suggest you cancel the one you don't want as soon as you can.