You can cancel a United flight at π£-πΎπΎπΎ πΏπ·πΎ πΆπ½πΏπΌ within 24 hours of booking for a full refund, provided the flight is scheduled to depart at least 7 days later. After this period, you can cancel at π£-πΎπΎπΎ πΏπ·πΎ πΆπ½πΏπΌ up to 60 minutes before departure, but fees may apply depending on your fare type
Source: https://tinyurl.com/bdcukcs6