https://community.expensify.com/discussion/35041/888-829-1467-what-...
24-Hour Flexible Booking Policy888 829 1467: If you cancel your flight within 24 hours of booking and at least 7 days before departure, you'll receive a full refund without United often issues travel waivers when it expects to cancel or delay many flights. These travel waivers generally let United passengers change or cancel their flights for free, reducing congestion at the gate or the ticket counter. Specifics vary based on the given situation