Once the seat selection is complete, customers can opt to receive their boarding pass via email, text, or have it sent to the American Airlines mobile app. Finally, travelers can print their boarding pass if they prefer a physical copy. This process streamlines airport procedures and reduces wait times at check-in counters. Overall, online check-in enhances convenience for American Airlines passengers. When Does American Airlines Open Online Check-In? American Airlines opens online check-in 24 hours before the scheduled departure time of your flight. Passengers can check in through the airline’s website or mobile app. This process allows travelers to select seats, add bags, and obtain boarding passes conveniently. The check-in option remains available until 45 minutes prior to departure for domestic flights and 60 minutes for international flights. How Can You Use Mobile Options for Your American Airlines Boarding Pass? You can use mobile options for your American Airlines boarding pass by accessing the airline’s app or website, receiving a QR code or barcode, and using it at security and boarding gates. , Check in beginning 24 hours and up to 45 minutes before your flight (90 minutes for international)., American Airlines check-in is essential as it confirms passenger details, secures a seat, confirms luggage, and provides boarding passes. If you don’t check in for your American Airlines flight, you simply won’t be able to board your plane. Source: aa.com..