Just a quick question about how UA inventory works.

I have access to Apollo and have been tracking inventory on a international flight for a couple of days, this afternoon it showed the following:

F9 J6 C3 Y0

On the seat map there were 9 F seats, 6 J seats, and 11 Y seats (which were all E+). I assume that the back is oversold and some do not have seat assignments so that is why there are seats on the map in Y.

However, a few minutes ago the inventory went to :

F0 J3 C3 Y0

The exact same seats are still on the seat map 9 in F, 6 in J, and 11 in Y.

I assumed they were upgrading people from Y to J and/or J to F, but I don't understand why the seats were not assigned and are still on the seat map?
When upgrades are processed, do they not assign seats?

Any insight into this would be greatly appreciated.

many times that is true, that is just one of the many reasons that seat maps should never be used as a gauge of bookings.

BTW that info is available on united.com and many other sites.

Less than half the time. I usually get an assigned seat if I get an UDU upgrade on a domestic flight. But when using SWU's or other instruments usually the upgrade clears with no seat assignment. That's likely what's happened here.

Thanks to you both for the info.

I have never seen actual availability on united.com (i.e. F9 J4 etc), I've only seen it as First - Y, Business Y, Coach N (or similar). Is this in the regular availability search on .com or is there a separate area where that information is displayed?

Thanks in advance.

Somewhere in your profile settings (My travel information - Display preferences - Availability format) you can select "Expert" mode - that'll show you the detailed fare information.

Yes... expert mode. Also now at CO.com when you do a flight search you can click on the link for "Fare Class" and all the buckets will be displayed (including award buckets).