All the details about the airline are mentioned in the portal and can also be guided by the customer service department. One can approach Check-In online options on United Airlines, Check In, Kiosk Check-In and customer service, which will help you book a flight and take care of your reservation. You can also call the United Airlines Customer Service number + 1-844-550-9333 for any questions related to ticket reservations, fight schedule, and reservations. If any type of query:- https://united.airlines-customerservice.com/