For each of the bankers, there are different commands available to manage your money. Keep in mind that you do not 'say' the commands. just type them into the chat bar:
- Deposit <value>: Deposits your money to the bank.
- Withdraw <value>: Banker will give you the value of money, as long as there's enough balance.
- Balance: Banker will tell you how much money you've got in his bank.
For item banks there are no special commands. You can put items into the bank using the 'offer' command, and get them back using the 'buy' command.