Early access to the PlayStation 4 version of Final Fantasy XIV: A Realm Reborn is now live, Square Enix has confirmed, meaning PS3 players are free to transfer their account over to the PS4 version.
The free transfer process will be available until December 31, 2014, and lets players transfer their characters and in-game items. It's unclear how exactly PS3 players will be able to upgrade to the next-gen version after December 31.
Be aware, however, that once you've upgraded to the PS4 version you'll no longer be able to play the game on PS3. If you wish to continue playing on both PS3 and PS4, Square Enix says that you must purchase a separate copy for PS4.
Early access to the PS4 version is available to those who pre-ordered the game, with the full game due to launch globally next Tuesday, April 14.
Source: Square Enix Press Release