Because the airline is fully aware of its customers' concerns, it has created a cancellation policy that enables anyone to do so without incurring any additional fees or effort. United Airlines Cancellation Policy is not too difficult to comprehend. Airlines recognize that last-minute trip cancellations happen and so provide flexible booking arrangements for the convenience of its customers. Within 24 hours of receiving their tickets, travellers are completely able to change or cancel their existing reservations without being charged any costs under this policy.