Your flight reference number, also known as a PNR (Passenger Name Record) or Booking Reference, is a 6-character alphanumeric code (e.g., AB12CD) found prominently on your booking confirmation email or e-ticket. It is usually located at the top of the document or in the "Itinerary" section, often near your name and flight number. If you booked through a third-party travel agent (like Expedia or Booking.com), you will see an "Agency Reference," but you must look for the specific "Airline Confirmation Code" to manage your flight directly on the carrier's website. If you cannot find your email, you can often retrieve the reference number by logging into the "Manage My Booking" section of the airline’s website using your frequent flyer credentials or by searching the "My Trips" section of their mobile app. This reference number is the most important "key" for your journey; you will need it for online check-in, selecting seats, and printing your boarding pass at the airport kiosk.