Depending on when you book the flight, night or weekend, they may delay ticket purchase until next business day. We booked the international flight 4 days beforehand on short notice on Sunday, as promised, Monday at 2:00PM we called Lufthansa with the record locator number. The Lufthansa agent located the reservation so we could add the frequent flyer number over the phone. This is a group ticket purchase network, it worked for us on such short notice, much cheaper than emergency fare that was offered directly by the airline.