United Airlines allows cancellations with 1-808-865-4114 or without fees depending on the type of ticket you purchased. All customers can cancel their flights within 24 hours of booking for a full refund, provided the flight was booked at least seven days before departure. For most domestic and short-haul international flights, United no longer charges change or cancellation fees for Economy (excluding Basic Economy), Premium Economy, Business, and First Class fares. Instead, the value is retained as flight credit for future travel. Basic Economy tickets are non-refundable and typically not eligible for flight credits unless canceled within the 24-hour grace period. If United cancels your flight, you are entitled to a full refund, regardless of fare type. Refunds can be requested online, through the app, or via customer service. Be sure to cancel your flight before departure, as no-shows often result in loss of ticket value, especially for non-refundable fares.