United’s commitment:

Customers who purchase a ticket for travel on United from a U.S. point-of-sale may cancel their reservations without penalty within 24 hours of purchase.

What this means for you:

In order to allow our customers time to investigate travel options and prices through other channels, we allow you to cancel reservations without penalty within 24 hours of your purchase. 

• If you booked and purchased your travel on united.com using your Mileage Plus® account, you may be able to cancel or change your ticket online. You can also call 800-UNITED1 (800-864-8331) or the number on the back of your Mileage Plus card within the United States to cancel or change it
• If you booked and purchased your travel online and do not have a Mileage Plus account, or if you purchased your ticket over the phone or at the airport, you can also call 800-UNITED1 (800-864-8331) within the United States to cancel or change it
• If you booked and purchased your ticket through a travel agent, please contact your agent for any travel changes

You may cancel and receive a refund on your original itinerary without penalty within 24 hours of ticket issuance. If you wish to change your itinerary, fees may apply.  Remember, however, that fares and seats are subject to availability and may change at any time prior to purchase.