By 
Last month, Nintendo revealed a new cloud service for their Pokémon RPGs, dubbed Pokémon Bank. As previously detailed, this will be a downloadable app for the Nintendo 3DS that will allow you to upload Pokémon from the Pokémon X and Pokémon Y games to the Internet. It will launch in the U.S. on December 27th.
Pokémon Bank will be a paid service, but the first month will be free, if you download and use the app (which includes obtaining the free pass) by January 31st, 2014. It will give you access to 100 storage boxes of your own, enabling you to store up to 3,000 Pokémon (that’s 30 Pokémon per box). The service will cost $4.99 per year.
When you download Pokémon Bank, you will also be given access to download a second application for your 3DS, titled Poké Transporter. This app will allow you to transfer Pokémon from Pokémon Black/White and Black 2/White 2 to Pokémon Bank, by inserting the cartridges of those respective games into your 3DS. Note that Poké Transporter will not allow you to transfer these monsters back to the previous games.
Poké Transporter is an app that works together with Pokémon Bank, so you won’t be able to download it separately without using Pokémon Bank as well. Nintendo point out that Pokémon Bank and Poké Transporter may not work with Pokémon that have been illegally created or modified.
Additionally, Nintendo note that Pokémon Bank will be compatible with Pokémon X and Pokémon Y, as well as with future Pokémon games as well. The annual $4.99 fee is intended to support long-term management and maintenance of the service.
You can find more details on Pokémon Bank in this FAQ on the official website.
