The Hive Bank is where you can transfer credits to other players. Lets take a look at the bank:

The box is for transfers only. You can transfer credits by typing in the amount of credits you want to trade (the first box) and the account name of the player you want to transfer credits to (the second box). This requires you to be at least level 5. Be warned, scammers often try to steal money from you by using this. To be safe, use the market, no matter what the excuse is!

In the past players had credits in hand and credits in the bank. When attacking a player there was a chance to steal credits in hand if the attack was successful. The only purpose for the bank at this time is to send credits.

You can find the bank at Sector 1 then Hive Bank, or on your if you have it there.