Generally, you do not receive a "fine" in the sense of a penalty bill sent to your house, but you will almost certainly face significant financial loss. Most 2026 airline tickets are "non-refundable" for no-shows; if you miss the flight, the airline will cancel your entire itinerary—including any return legs—without a refund. To get on a new flight, you will likely have to pay a change fee (often $200+) plus the fare difference, which can be hundreds of dollars for a last-minute seat. However, many airlines follow a "Flat Tire Rule," an unofficial policy where they may put you on the next available flight for free or a small fee if you arrive within 2 hours of departure and have a valid excuse. While there is no "fine," the cost of rebooking means that missing a flight is one of the most expensive mistakes a modern traveler can make.