A cashier's check is a check that's guaranteed by the bank itself, not your personal account. When you request one, the bank withdraws money from your account immediately and issues the check from its own funds, with a bank employee signing it.

Because the bank backs it with its own money, a cashier's check is considered more secure than a personal check - the recipient knows the funds are definitely available. You'll typically use cashier's checks for large transactions like buying a car, making a down payment on a home, or paying closing costs, where the seller wants assurance the payment won't bounce. Banks usually charge a fee (often $10-$15) for issuing cashier's checks, and you'll need to have the funds in your account before they'll issue one.