If you miss a flight on United Airlines, you may be able to standby for the next available flight or rebook for a fee. Additionally, United's policy allows for a refund or credit for unused, non-refundable tickets within one year of purchase, minus applicable fees. For additional information about Missed Flight United contact the helpdesk at 1 (800) 864-8331 or 1 (888) 838-0309 (OTA-Skip Waiting) or visit the Airways Manage Booking site.