Does United have a 24-hour cancellation policy?

Yes, United Airlines does have a 24 hour cancellation policy, which allows passengers to cancel their bookings without incurring any cancellation fees, provided certain conditions are met. This policy applies to tickets that were booked at least seven days 168 hours before the scheduled departure time of the flight. During this 24 hour period, passengers have the flexibility to cancel their reservations for a full refund or to make changes to their itinerary at no extra cost.

Source: https://sb-dev.microsoftcrmportals.com/en-US/forums/general-discussion/8deb5eba-393a-ef11-a297-00224806ca90