If you’ve booted up your copy of Pokémon Sun or Moon today and tried to connect online you’ve no doubt seen a notification that the game needs to be updated.
Oddly unlike most games on the Nintendo 3DS there is as yet no prompt to perform the update in the Nintendo eShop. A quick search in the eShop will find the update, which you can download for the appropriate game. The update is required to use online services with Pokémon Sun and Pokémon Moon.
The update doubles the storage space for Pokémon in the games boxes. Storage space via the in game PC has doubled from 8 to 16 boxes. Instead of being able to store 240 Pokémon you can now store up to 480. This update will likely also facilitate compatabilty with Pokémon Bank, which is due to be updated in January.
The update will only take 296 blocks on your SD card. There is no word on the reason for the update, but it falls on the heels of the latest mission in Pokémon Global Link which saw the goal of 1 million Pokémon caught via Island Scan not met.