Kid: Is my money sitting in the bank's vault?
Dad: No. A deposit is money the bank owes you, not money it's holding for you.
Kid: So how much does it actually keep?
Dad: Only a sliver, as cash and reserves. Australia hasn't had any minimum reserve ratio since 1988.
Kid: What if everyone wanted their money back at once?
Dad: They couldn't all get it. There's only around $100 billion of notes and coins in the country, against more than $3 trillion owed in bank accounts.
Kid: So what stops a panic?
Dad: The government guarantees deposits up to $250,000 each, so nobody starts a run.
Kid: Where does the government keep the money for that?
Dad: It doesn't. There's no fund and no vault. Parliament has pre-approved up to $20 billion, and it's only paid out after a bank fails.
Kid: Is $20 billion enough?
Dad: Not for a big bank. Households alone keep about $480 billion at CommBank. $20 billion wouldn't come close to covering one of the big four.
Kid: So who pays it back?
Dad: First they sell off what the failed bank owns. If that's not enough, the other banks get charged a levy. For anything bigger, Parliament would have to find more money, and that means more borrowing.
Kid: But it's still my money, right?
Dad: Legally, no. The moment you deposit it, the money belongs to the bank. You're just someone it owes. The courts settled that in 1848, in a case called Foley v Hill.
Kid: So can the bank stop me getting it?
Dad: Yes. Under the Anti-Money Laundering Act, a bank can freeze your account or block a payment if it's not satisfied about you or where the money came from.
Kid: Do they have to tell you why?
Dad: No. If they've reported you to AUSTRAC, the money-laundering watchdog, it's a crime for them to tell you.
Kid: Can anyone else take it?
Dad: The tax office can order your bank to hand over money from your account for a tax debt, without going to court. Police can get a court order to freeze it.
Kid: And if I just leave it there?
Dad: Leave an account untouched for seven years and the bank hands it to the government as unclaimed money. You can claim it back, if you know to look.
Kid: So the bank lends money it doesn't have?
Dad: It creates the money when it lends and charges you interest on it. If the loans go bad, taxpayers stand behind the deposits. Heads the bank wins, tails we lose.