Like Pokémon X & Y, Pokémon Bank is on the Nintendo 3DS and thus is capable of patches and updates to the software. This is done through the Nintendo 3DS eShop and gives you a prompt. It can also be done using a QR code

Version 1.1
Release Date:

January 22nd 2014

Patch?
No - Full redownload required.

Poké Transporter Updated?
Yes

Fixes:

  • This update fixes the way that Pokémon Bank connects to the servers, removing the multiple connections to the Nintendo Network ID server, the eShop server and the Bank server, just running through one connection to the Nintendo Network ID server before connecting to the Bank server

Version 1.2
Release Date:

November 18th 2014

Patch?
Yes

Size?
210 Blocks

Poké Transporter Updated?
No

Fixes:

  • This update adds in compatibility for Pokémon Omega Ruby & Alpha Sapphire, including all new moves introduced within it

Version 1.3
Release Date:

January 25th 2017

Patch?
Yes

Size?
496 Blocks

Poké Transporter Updated?
Yes

Fixes:

  • This update adds in compatibility for Pokémon Sun & Moon, including all new Pokémon, abilities & moves introduced within it
  • Added the new National Pokédex feature
  • Added a stat comparison feature
  • Poké Transporter updated to allow for transfer from Pokémon Green, Red, Blue & Yellow

Version 1.4
Release Date:

November 20th 2017

Patch?
Yes

Size?
516 Blocks

Poké Transporter Updated?
Yes

Fixes:

  • This update adds in compatibility for Pokémon Ultra Sun & UltraMoon, including all new Pokémon, abilities & moves introduced within it
  • Poké Transporter updated to allow for transfer from Pokémon Gold & Silver