This article provides a comprehensive overview of the online check-in process offered by Aer Lingus, Ireland\\s national airline. It covers essential aspects such as the timing of online check-in, the convenience of checking in via the Aer Lingus app, and the option to check in for group bookings or bookings with infants. Additionally, it discusses the benefits of online check-in, including real-time flight updates and the ability to add digital boarding passes to mobile wallets. The article emphasizes the ease and efficiency of the online check-in process, highlighting its accessibility from up to 15 days before departure for European flights and 24 hours before for transatlantic flights. Furthermore, it mentions the availability of an Express Baggage Drop service at select airports, further enhancing the overall check-in experience for passengers.