Originally Posted by kaosx
Question: I booked an LH flight to TLV before I got the new passport # and I can't remember if they asked for my passport number during the booking. The new passport has a new number, do I need to call LH to give them the new number or can I wait 'til day of the flight?
Waiting until check-in on day of flight is fine. But there is no harm in having it updated in advance either other than your time on the phone and a cost of a call.