Contact the airline of your flight. Locate the airline number or website on the email confirmation or reservation page; most tickets are e-tickets today -- paper tickets are a rarity. Be ready for long wait times when using toll-free airline customer service numbers. To avoid phone waits, try the website and online method first.
Submit your cancellation-deletion request via the online portal. Some airlines offer low cancellation fees. For example, Southwest Airlines has a special page for trip cancellation. Southwest airlines allows you to cancel the trip and keep the credit for a future flight.
Go to an airport and head to the desk for your airline. Bring your passport or ID and all email confirmation codes. Ask, nicely, if it is possible to cancel and receive a refund or flight credit. Be as courteous as possible and simply state your case. Honesty goes a long way. Stick to the facts.
Keep records of all web codes and reservation numbers. If you have not booked and paid for the flight yet, deleting is as simple as clicking "Do Not Book" or such links. Some airlines allow a 24-hour hold on a reservation, which locks in the price but gives you 24 hours to purchase. If you choose not to purchase, simply ignoring the deadline automatically voids and deletes the reservation.
