For the majority of British Airways flights, online check-in opens exactly 24 hours before your scheduled departure time. During this window, you can select your seat (if you haven't already paid to do so), confirm your passenger details, and download your digital boarding pass to your smartphone. If you are a member of the Executive Club (Silver or Gold status) or are traveling in First or Club World (Business Class), you may be able to select your seat much earlier, but the actual "check-in" confirmation still follows the 24-hour rule. At the airport, physical bag drop desks typically open 3 hours before international long-haul flights and 2 hours before short-haul European flights. If you are flying from London Heathrow or London Gatwick, BA also offers a "Twilight Bag Drop" service, allowing you to check your bags between 4:00 PM and 9:00 PM the evening before an early morning flight (departing before 9:00 AM). This is a fantastic way to save time on the day of travel and head straight to security upon arrival at the airport.