A family member is booking flights for a holiday we’re all going on later this year. They’ve contacted me to ask for all our passport numbers for when they go to book the flights. My dds passport has just been sent away to be renewed, will they still be able to book the flights without it and add it in at a later date? Or will they have to wait until we get it back? It’s been so long since I booked a flight I can’t remember if I had to put in passport numbers at time of booking or not.