Originally Posted by
LondonBoundSW8
Really? Every major airline I have flown with have a continual presence, desks open for other flights you can check in to yours whenever. As imagine when you arrive at a connecting airport and your flight is cancelled, they don't throw your bags back at you, so it's not because they can't open early, it's because they don't want to. It's just TAP don't have a permanent check-in desk presence due to the lack of flights imho
TP has only a single flight out of SFO, so they have their check-in desks open only for that flight. United has many flights out of SFO, so it has continual presence. That's how things work. LHR is a bit different - they have a combined *A facility, something that you don't have at SFO.
I've had success checking bags for a later TP flight when check-in was open for an earlier one at BCN, but this is not in any way guaranteed for any airline.