Or could they all use foreign banks? Dumb question. I don't know the answer. Are there some laws that make it hard to use foreign banks? Tourists seem to manage OK without opening a foreign bank account. It ought to be easier still if the foreign country uses the same currency. Could the foreign banks install ATMs in Greece without becoming Greek banks? Do you even need to be a bank to operate an ATM? And you don't need to be a bank to lend someone money. Does physical location really matter, especially for money that has no physical form, so the only thing that gets transported is information? How often do we need to sit down face to face with our banker?