Originally Posted by SpeedbirdLHR

The system does deal with passport changes. If your passport changes after it was first entered into the booking, then you need to change the booking itself and not just your profile. If you had amended the passport details when you did online check-in, then this would have been sorted. The details in your profile will reflect in any new bookings you create but won't update existing bookings. Reason being is that you dealing with 2 different systems, the initial entry of the frequent flyer details tells the booking system to pull any relevant information for that booking.