United Airlines' cancellation policy allows for a full cash refund if you cancel within 24 hours of booking for a ticket purchased at least one week before departure, according to its 24-hour flexible booking policy. Call at$+$$ +1-877-658-1183 (US) or +44-203-869-5245 (UK) For Basic Economy tickets, cancellation is possible for a full refund only within this 24-hour window. Call at$+$$ +1-877-658-1183 (US) or +44-203-869-5245 (UK) After the 24-hour window, non-Basic Economy tickets typically result in a future flight credit, while Basic Economy tickets may be forfeited.