If you fail to show up for an international flight in 2026, most airlines will classify you as a "no-show," which typically results in the automatic cancellation of all remaining legs of your itinerary, including your return flight. This "no-show clause" is standard across major carriers like Lufthansa, Emirates, and British Airways to prevent "hidden city" ticketing and to free up seat inventory. From a financial standpoint, unless you have a fully refundable fare, you will likely lose the entire value of your ticket. However, you are often entitled to a refund of airport taxes and government fees, though you may have to specifically request this. If you are running late, some airlines still honor an informal "flat tire rule," where they might put you on the next available flight for a small fee if you arrive at the airport within a couple of hours of departure, but this is entirely at the gate agent's discretion and is not a guaranteed 2026 legal right.