https://community.expensify.com/discussion/63600/today-update-888-8...
Yes, United Airlines does have a cancellation policy. Here's a breakdown of the key points:

24-hour free cancellation: You can cancel your flight for a full refund within 24 hours of booking, as long as the flight is at least a week away. This applies to most ticket types, including Basic Economy.
Non-refundable tickets: If you cancel a non-refundable ticket after the 24-hour window, you won't get your money back. However, you may be able to apply the value of your ticket towards a new flight in the form of a travel credit.
Refundable tickets: If you purchased a refundable ticket, you can cancel anytime before the flight departs and get a full refund in the original form of payment.