Changing a passenger's name on a ticket reservation: why airlines charge such exorbitant prices
Due to the inability to transfer tickets, you must cancel your original reservation and make a new one. There may be a fee associated with cancellation.
Take care of the name issue before final submission
When you purchased your travel online, did you inadvertently input the incorrect name? Not unusual. Is it possible to edit it? Or, is it feasible to transfer your reservation to another passenger if you are unable to take the flight that you have booked? The answer to both of your questions is "possible," but it will probably cost you money. The price will vary based on whether the United airlines flight is domestic or international, the travel class, and where the ticket was purchased. If you plan to travel internationally, however, you must book your trip using the name that will appear on your passport.
Check the pricing carefully
United airlines' price to change a passenger's name for domestic tickets is $88; however, this fee is not levied for their more inexpensive "Getaway" fares. If you have purchased a ticket with a Getaway fare, your only alternatives are to cancel the reservation, request a refund, and make a new reservation, or upgrade to an "Elevate" fare, which will allow you to change the passenger's name.
A domestic economy class name change on United airlines costs $99, although this service is only available for flights purchased with the Flex upgrade option. Tickets purchased through the Red e-Deal campaign do not accept name changes, so unfortunately your luck has run out.
Bottom Line
If you are planning to change your name around the time at you will be arranging travel, use the name that will appear on the identification that you will use. Consequently, if you do not have a passport or if your passport has expired, you may be compelled to apply for a passport using the name you had before you changed it, even if you plan to travel after a wedding or other event at the time of which you adopted a new name.
If this is the case, it is probable that, with the exception of your United airlines passport, all of your invoices, records, and identity documents will reflect your new name. 

United Airlines name change Fee and Policy for the passenger, we need To Correct name with match of Govt Id Proof and passport. We are not providing name Change policy Not allow another person and unmatched Flight Ticket name. So pls correct misspelled name on Tickets Before Departure.
Name Change Fee on United Airlines Request on call and via mail United Airlines we are Charge 200USD Before 2 Hours Departure and applicable fare deference.