Generally, there is no "penalty fee" for missing a flight, but the financial loss comes from the forfeiture of your ticket. In 2026, if you miss your departure without notifying the airline beforehand, you are typically marked as a "No Show," and your entire itinerary (including return flights) is canceled with no refund. However, many airlines still honor the informal "Flat Tire Rule." If you arrive at the airport within 1–2 hours of your missed departure, agents may put you on the next available flight for just the fare difference, waiving the official change fees. In early 2026, new DGCA and DOT consumer protection rules have made it easier to get a refund or credit if the "miss" was due to a documented medical emergency, but for standard tardiness, the cost is the price of a new seat.