To change your seat on a United Airlines ticket booking, you can follow these steps:

Visit the United Airlines Website:
Go to the official United Airlines website (https://www.flightsvilla.com/blog/how-do-i-upgrade-my-seat-on-united-airlines) using your web browser.

Log In to Your Account:
If you have a United Airlines MileagePlus account, log in using your credentials. If you don't have an account, you may need to create one or proceed as a guest.

Access Your Booking:
Once you are logged in, find and access your existing booking. This can typically be done by clicking on the "My Trips" or "Manage Reservations" option on the website's homepage.

Select the Flight You Want to Change:
Locate the specific flight reservation for which you want to change your seat and click on it to open the details.

Change Seat Assignment:
Within the booking details, look for an option that allows you to change your seat assignment. This option is usually labeled as "Change Seats," "Select Seats," or something similar.

Choose a New Seat:
You will typically be presented with a seating map showing available seats. Click on the seat you want to change to. Keep in mind that some seats may require an additional fee.

Confirm the Changes:
After selecting a new seat, review your changes and confirm them. You may be required to pay any applicable fees if you are upgrading to a seat with extra legroom or other amenities.

Complete the Transaction:
Follow the prompts to complete the seat change. You may need to enter your payment information if there are fees associated with the seat change.

Receive Confirmation:
Once you have successfully changed your seat, you should receive a confirmation email with your updated seat assignment.

United Airlines Seat Selection Policy

United Airlines offers various options for seat selection, and its policies may vary depending on the type of ticket, fare class, and MileagePlus status. Here is an overview of United Airlines' seat selection policy as of my last knowledge update in 2023.

Basic Economy:
When you purchase a Basic Economy ticket, United Airlines typically assigns your seat at check-in.

Seat selection before check-in is usually not available, and you may not be able to choose specific seats or change your seat assignment.
United may assign seats for families and groups traveling together, but they do not guarantee that you will be seated together.

Standard Economy and Premium Cabins (e.g., Economy Plus, Business, and First Class):
Passengers traveling on standard economy tickets or premium cabins usually have the option to select seats at the time of booking, often at no additional cost.

United MileagePlus Premier members, credit card holders, and elite status holders typically receive complimentary access to preferred seats or upgrades to Economy Plus seats when available.

Economy Plus:
Economy Plus seats offer more legroom and are available for purchase. MileagePlus members may receive complimentary access to these seats depending on their status.

Preferred Seating:
United Airlines offers preferred seating options in standard economy cabins. These seats may include aisle or window seats closer to the front of the aircraft.

Preferred seats are typically available for an additional fee or may be complimentary for MileagePlus elite members and some fare types.

MileagePlus Premier Members:
United's MileagePlus Premier members, including Premier Silver, Premier Gold, Premier Platinum, and Premier 1K, enjoy complimentary access to Economy Plus seating and may receive complimentary upgrades to higher cabins, subject to availability.

Change of Seat Assignment:
Passengers who want to change their seat assignments can do so online through the United Airlines website or mobile app, or by contacting United's customer service.

Fees may apply for certain seat changes, such as upgrading to a premium seat or changing seat assignments on Basic Economy tickets.

Group and Family Seating:
United Airlines typically allows groups and families to be seated together, but it's advisable to make these arrangements during the booking process or by contacting customer service.