The account bank offers extra storage that can be accessed by all characters on your account. It's a convenient way to make items available between your toons. Also has a way to transfer Energy Credits between characters.
You can find/contact me in game as @PatricianVetinari. Original Join Date: Feb 2010. Need Help with Ship's Power? Check out my Ship Power Guide and Calculator.
Shared storage among your characters. Like for example on my baby Fed I have a couple of Mk II Disruptor weapons Bound to Account. I dropped them in my account storage bank and picked them up on my Romulan But you can store EC there too.
I also throw all my crafting junk in there just because.
The account bank must be purchased from the zen store before you gain access
The account bank is also available for 'Free' for subscribed 'Gold' accounts, and former 'Gold' accounts. Account bank obtain through 'Gold' status persist, even if the account should transition back to F2P 'Silver' status...