United 24-Hours cancellation policy allows you to cancel.United 24-Hours cancellation policy allows you to cancel. Key Features of United Airlines' 24-Hour Cancellation PolicyEligibility: The policy applies to all domestic and international flights booked directly through United's website or mobile app. https://globalcomix.com/forums/threads/1734/-get-18888-291467-cancellation-policy-allows-you-to-cancel-united-24-hours