Passengers should first determine whether their reservations are changeable by consulting the United Airlines Flight Change Policy before making any changes to their flight plans.

• Make sure the initial reservation is confirmed before making any adjustments to the flight so that you can do so.
• Next, you will be able to cancel the reservations for free if you do so within 24 hours of making them.

• Keep in mind that you may only make changes to reservations of any kind once; multiple modifications are not permitted. Therefore, be careful when making any changes to the reservations.

• Although you are not permitted to change the passenger's name, you are permitted to repair a spelling error.

• If you do not have a non-refundable booking, there is no justification for making changes to your flight reservations.

Read More:- Delta Airlines flight change policy