From another thread, It Is Now Mathematically Impossible To Pay Off The U.S. National Debt: An interesting few minutes, but what has always puzzled me is when they talk about a run on a bank: I don't get how a bank "calls in its loans". Doesn't a person buying a house or a car (or a business buying equipment) borrow money at terms? Meaning I borrow $100,000 to buy a house and I agree to pay back $1000 a month principal and interest until it's repaid. If a bank called me up and said "Hey you still owe us $90k on your house, uh, we need it by tomorrow" well I would tell them to pound sand. We made an agreement that I pay back a little bit each month, and the bank can't demand early payment. So what does it mean when a bank "calls in loans"?