While you physically can skip a flight, doing so—especially the first or middle leg of a multi-flight ticket—carries severe consequences for the rest of your itinerary. Most airlines operate under a "sequential use" policy in their contract of carriage; if you skip the first leg of a round-trip or connecting ticket, the airline will automatically cancel all remaining flights on that itinerary, including your return journey, with no refund. This is to prevent "hidden city ticketing," where passengers book a cheaper flight with a layover and get off early. If you skip the final leg of your trip, the airline cannot cancel any more flights, but they may still penalize you by revoking your frequent flyer miles or banning you from future bookings if they detect a pattern of this behavior. Additionally, any checked luggage you have will almost always be sent to the final destination on the ticket, meaning you would be separated from your bags. To avoid these issues, if you genuinely cannot make a flight, it is essential to call the airline to "re-fare" or modify the ticket rather than simply not showing up.