If you want to cancel your reservation for a flight with United Airlines, you need to be informed of all the requirements, specifications, and conditions of the United airline's cancellation policy. United offers very clear and transparent cancellation and refund policies when compared to other airlines. Before changing a previously scheduled flight, they must adhere to certain protocols. In order to make cancellation policies more useful for United Airlines passengers on both local and international flights, airlines implemented a few changes. Almost all United Airlines plane tickets are subject to change fees. United Airlines lets you cancel your travel up to 24 hours before the start of your itinerary if you decide on the destination but your plans change.