Singapore Airlines offers several check-in options for passengers. Online and mobile check-in opens 48 hours before departure and closes 1.5 hours prior for most flights. For flights from the United States, online check-in opens 24 hours before departure. Passengers can check in by entering their booking reference or e-ticket number on the website or mobile app. During check-in, seats can be selected or changed, baggage added, and a digital boarding pass obtained. Travelers with carry-on luggage only can proceed directly to security and boarding. Those with checked bags must drop them at airport counters or self-service kiosks. Airport check-in counters open about three hours before international flights and close 40 minutes before departure. Self-service kiosks are available at select airports for check-in and baggage tagging and close around 40 minutes before flight time. Singapore Airlines also offers an auto check-in service for eligible passengers, which automatically checks them in 48 hours before departure and sends confirmation. This service is not available for unaccompanied minors, group bookings, or passengers without confirmed bookings. Premium passengers in Suites, First Class, and Solitaire PPS Club members have access to dedicated check-in counters with expedited processing. Arriving early at the airport ensures enough time for check-in, security, and boarding. These flexible options help passengers start their journey smoothly.