|Quoting Zrs70 (Reply 3):|
Is the UA flight on an AC code-share (UA metal, AC flight number/ AC metal, UA flight number). If so, you won't be able to have access to the seats in advance.
Depending upon how it's booked, if the booking airline can give you a UA
record locator, you can head over to united.com and make seat assignments. You may also be able to do it via phone if you don't have the locator, but this will tend to depend upon the ability of the call center staffer you get.
I always do this when making award reservations on US with UA
segments - US can't get me UA
seats, but can give me the record locator to do it myself online or via phone. If any other changes need to be made to the reservation beyond seat assignments, US needs to make the change.