Alter Aeon Online Help

Keywords are:  'privatebank banking'

If you have private banking, you can use the gold bank from anywhere in
the game, at any time.  This allows you to save gold as soon as you get
it, instead of having to go back to a town to deposit it.  If you're in
a dangerous area where you could die, this can potentially save a lot of
hassle.

Use the 'credit buy bank' command for more information.