"
-Do I need to purchase FINAL FANTASY XIV: Heavensward for each of the platforms that I currently play A Realm Reborn on?

Global: Yes. You will need to purchase and register a copy for each of the platforms that you would like to play on. For example: You play FFXIV: ARR on PC and PS4 and wish to play the expansion on both of those platforms, then you would need to purchase FFXIV: Heavensward on both PC and PS4."

http://forum.square-enix.com/ffxiv/t...rs-bonuses-etc.