Originally Posted by
Often1
For a standard domestic flight, check-in by T-45 as required assures AA that a passenger is likely to show up at the gate no later than T-15 when the passenger is subject to off-loading if he does not show.
There is no passenger downside to checking in as soon after T-24 as possible. The fact the changes may require a reissue is of no passenger consequence.
So if you check in for a flight from xxx-yyy, and that flight is delayed for 3 hours, and there are empty seats on the next flight from xxx-yyy that will now leave before the flight you checked in for, you're not at a disadvantage of getting rebooked on the later (now earlier) flight compared to someone who hasn't checked in? All other things (status, fare paid etc) being equal? It seems like it'd be easier/path of least resistance to put a non checked-in passenger on a different flight than one who has checked in. In any event I feel fairly sure there have been at least a couple of instances where I felt fortunate to not have checked in early, that my situation was better than if I had checked in, though I may be mistaken. I think the overwhelming majority of times it is beneficial to check in as soon as you can, but "no passenger downside" at all? Ever?