Originally Posted by UA Insider

Hi FlyingProf, was this showing R0 when you were looking at it in the shopping path, or when viewing your already booked reservation? When looking for R availability, viewing connecting flights in the shopping path is not as reliable as viewing each flight separately. If R shows 0 when booking a connecting flight, but, is available when viewing separately, then, as SEA1K4EVR, has mentioned you will be able to upgrade it after it’s ticketed (e.g. After ticketing, view reservation and then select the 'upgrade reservation' link found toward the top of the itinerary). Also, one good tip to note is that, when upgrading after ticketing, the process will also waitlist you for any segments that may not be available.

Shannon