Technically, you can "cancel" or simply not show up for one leg of a round-trip flight, but in 2026, this comes with significant risks. If you miss or "no-show" the first leg (the outbound flight), almost every airline’s automated system will automatically cancel the remaining legs, including your return flight, without a refund. This is to prevent "hidden city ticketing" and other price-manipulation strategies. If you want to cancel the second leg (the return) after having already flown the first, you can do so, but you rarely receive any money back for the "unused" portion of a standard non-refundable ticket. In some cases, if you need to change your plans, it is better to call the airline and ask for a "re-faring" of the ticket to a one-way, though this can sometimes actually increase the price. For 2026 travelers, the best advice is to never skip the first part of a journey without speaking to an agent, as you will likely find yourself stranded with a voided return ticket.