Use the United website or app to access your booking online in order to cancel a flight with United Airlines. Proceed to the "My Trips" area and choose the flight you want to avoid. To begin the cancellation process, adhere to the instructions. Depending on the fare regulations and the date of the cancellation, you might be eligible for a refund or credit under United Airlines flight cancellation policy. As an alternative, you can get help from United Airlines customer service by calling and canceling your flight.