The United Airlines Cancellation Policy allows anyone to cancel their reservation without incurring any additional costs or effort because the airline fully understands the worries of its customers. The policy is fairly simple to understand. Airlines offer flexible booking policies for the convenience of the passengers because they are aware that you could need to cancel your trip at the last minute. This policy provides every traveller complete freedom to modify or cancel their existing reservations without incurring any fees within 24 hours of receiving their tickets.