The Pokemon Bank has been updated in order to allow players to use Pokemon Sun and Moon with it. This means they will not only be able to store thousands of Pokemon, but also move creatures from older games into their new game if they please.
You should be warned that the Pokebank can only transfer Pokemon from Black, White, Black 2, White, and the 3DS versions of the original games, but Pokemon cannot be withdrawn to those games once the transfer is complete. Omega Ruby, Alpha Sapphire, X, and Y cannot withdraw Pokemon from the original games, and only the seventh generation can do so. Once you transfer anything over to Sun and Moon, you cannot transfer it to another game, and will only be able to deposit and withdraw.
You’ll want to go to the Nintendo eShop to download Pokebank and eventually the Poke Transporter. While downloading the app is free, the service will cost $4.99 a year. Once everything is downloaded, boot up whichever game has the Pokemon you want to save to the bank. Head over to the nearest computer and transfer whichever critters you want into Box 1 – this is important because the Poke Transporter will only acknowledge the first box. You’ll also want to remove any items because those will be sent to your bag, and if your bag is full then it will be lost forever.
Now that your Pokemon is in the first box, save and exit out of the game. You’ll want to boot up the Transporter app, which will ask you if you want to save the first box, you will have to say yes for it to transfer anything to the bank’s Transport Box. You can then close the app and switch to Sun or Moon.
Insert the game, but do not turn it on and instead you’ll finally make use of the bank app. Confirm that the app has access to your copy of the game, and this will lead to Box 1 of the game on the bottom screen with the Bank 1 box on top. Select the Bank 1 box and then press left, which will then show the Transport Box that has your Pokemon from the older games. You can either move everyone one by one or press start twice to change the cursor from red to green, which will allow you move whole groups.
Feel free to move everyone over into another box in your bank for safekeeping or move it downward and deposit them in an empty box on your Sun or Moon file. If you need to find a certain Pokemon within your bank, pressing Y will help you narrow everything down. If not, then just press X to save. You can now start up your copy of Sun and Moon and make use of your new friends.