Pokémon fans should mark January 2017 in their calendar because this is the confirmed schedule for the much anticipated update to the Pokémon Bank.

The Pokémon Bank is a cloud-based 3DS app that lets players deposit their monsters and "withdrawn" to another Pokémon game. However, the app is only currently compatible to Pokémon X, Pokémon Y, Pokémon Omega Ruby and Alpha Sapphire. The update will expand compatibility so that the Bank's services will be open to all 3DS titles including the upcoming Pokémon Sun and Pokémon Moon.

With the new update, monsters from older games such as the eShop versions of Pokémon Red, Blue and Yellow can also be deposited into the Pokémon Bank. Older games will only require the Pokémon Transporter tool to do so.

The Pokémon Bank can accommodate up to 3,000 monsters.

"Beginning with the Game Boy Advance games, we made it possible for you to take the Pokémon you caught and bring them over to the next generation of games, even if they were on different hardware," CEO Tsunekazu Ishihara said. "However, we were never able to solve the communication issues with the Game Boy and it was not possible to bring Pokémon from the Game Boy games over to games on other hardware."

There is one key warning about bank transfers that should set players thinking carefully.

"If you transfer a Pokémon to Pokémon Bank and then on to Pokémon Sun or Pokémon Moon from Pokémon Omega Ruby, Pokémon Alpha Sapphire, Pokémon X, or Pokémon Y, you'll be unable to transfer it back to Pokémon Omega Ruby, Pokémon Alpha Sapphire, Pokémon X, or Pokémon Y," an official statement said.

Also, the Pokémon Bank will reject monsters that are deposited while holding items. These will be returned to the game they originally came from.

Another key feature to be introduced involves the emergence of a national Pokédex. Compatible games can be connected so that the player can populate them accordingly with monsters caught, even those that do not inhabit the Alola region, the region where the Pokémon Sun and Pokémon Moon take place. This means that all of the monsters collected in the entire Nintendo 3DS titles can be browsed in one Pokédex.

Unfortunately, the classic trio on the handheld system is excluded and this extends to those that were re-released for the Virtual Console.

Using Pokémon Bank along with the Pokémon Transporter service has an annual usage fee of $5.83 and the activation comes in the form an annual pass.