Originally Posted by
Philippe Bornet
It won't work, because the system checks that the birthdate matches the right category (adult, infant etc.) of passenger. If it doesn't match, it makes it impossible to proceed. And putting a wrong birthdate could mean issues with TSA etc.
It works, just takes an extra step. Very easy to update post ticketing with an UA agent well before TSA. Many regularly book this way, especially with minors on separate ticket BUT traveling with parent. Call to correct the year and get the agent to insert the traveling with parent coding.
UA has essentially no child / senior discount fare on their flights. A few partners still have child fares but becoming less available.