Originally Posted by
Totoro
I believe the UA agents attempted to convey domestic first class similar to UA's product. The flight I booked just happens to be operated by international equipment with the front cabin being sold as domestic first.
Should I assume that the instant-upgrade should process automatically when space becomes available, or does one need to call AC?
There is no such thing as instant upgrade on AC. If you're an AC elite member then you may be eligible for upgrades but that's up to the AC program. UA elites will not get instant upgrades on any AC fare. You can potentially use miles to upgrade an AC full "Y" fare but it doesn't sound like you're on one of those.
Bottom line...
If you booked an AC-coded flight and it shows "A" class then you're in coach.
If you booked a UA-coded flight and it shows "A" class then you're in business.
It does not matter who ticketed the flights.
-RM