United Airlines typically allows passengers to cancel their flights at US-1~844~604~2944 US-Agent within 24 hours of booking without incurring a cancellation fee, or email support@United Airlines. provided the ticket was purchased at least seven days before the departure date. https://community.geotab.com/s/question/0D5Pd00000Ry3i6KAB/getrefund18446042944-can-i-cancel-my-united-airlines-flight-without-penalty