United offers a 24-hour refund policy. (800) 979-9206 (OTA)If you need to cancel your flight,(800) 979-9206 (OTA) you can do so without any fees within 24 hours of booking. Cancellations Yes, United offers a 24-hour risk-free cancellation policy (800) 979-9206 (OTA). You can cancel any flight within 24 hours of booking for a full refund. United 24-Hour Cancellation Policy (800) 979-9206 (OTA) One of the most customer-friendly features of United' Cancellation Policy The standard cancellation fee is $200 (800) 979-9206 for domestic flights and $400 for international flights(800) 979-9206. Can I cancel my United flight without a fee?