A banker's draft, also known as a bank draft, is an alternative payment option to a personal or business check. It is a financial instrument or payment form where the bank guarantees payment from the payer's account. There are other synonyms for a banker's draft, such as a cashier's check, treasurer's check, and official check. A cashier's check is similar to a banker's draft where the funds are guaranteed by a bank. A treasurer's check is issued by a person holding an official position in an organization. Lastly, an official check is a check issued by a financial institution to pay a specific amount to a person or organization. Regardless of the synonym used, these instruments are typically used for large transactions that require a more secure form of payment.