When passangers want to Turkish Airlines check-in for flight, you will need to have the following information and documents such as, Flight booking information, Valid passport or government-issued ID, Visa and travel documents, Boarding pass,Baggage.The check-in deadline for Turkish Airlines flights varies depending on the destination and departure airport, so it's important to check the airline's website or contact customer service 1-8441-414-9223 to confirm the check-in deadline for your specific flight.