When you switch flights—a process known as rescheduling or amending—the airline cancels your original seat and issues a new ticket for your requested date or time. In 2026, most major carriers offer a 24-to-48-hour "look-in" window where you can change your flight for free (paying only the fare difference) if you booked directly. Outside of this window, the process involves two costs: a flat change fee (which varies by fare class) and the fare difference between your old ticket and the new one. If the new flight is cheaper, most airlines do not refund the difference but may issue it as a "travel credit." Once the switch is confirmed, your old boarding pass becomes invalid, and your luggage tags (if already checked) must be updated by ground staff. If you are switching due to a delay or cancellation caused by the airline, you are entitled to be rebooked on the next available flight at no cost, and depending on the jurisdiction (like EU 261 or similar new 2026 Indian DGCA rules), you may be entitled to food vouchers or hotel accommodation during the wait.