Originally Posted by
seigex
I've done two separate tickets, LAX-NRT on ANA then NRT-TPE on EVA, ANA was happy to check all the way through. They are both on Star Alliance, but according to
this post NH has an interline agreement with JAL, so if that's the case, you should have no problem booking all way through as long as the layover is reasonable (ie less than 24 hours iirc).
Interline agreement is not a guarantee for checking in across two tickets, BA has an interline agreement with many airlines, but will not check in across separate tickets to any airline.
Alliance to alliance is never problem for ANA or JAL. From a Japan station domestic to international between JAL and ANA also no problem. Out station is a bit more questionable.