A duplicate booking means two or more reservation is made for a single passenger. These types of duplicate bookings are prohibited by JetBlue Airline. Some examples of duplicate bookings are listed below:  The ticket of the same customer is identical.  Two identical tickets for the same customer.  Multiple itineraries with the same customer name.  Booking one or more seats for the different or same flight.  Bookings are made for two or more flights where customers are the same.  Now booking for a traveller which already exists in JetBlue Airways.