Being a teller requires a great deal of attention to detail. Before cashing a check, a teller must verify the date, the name of the bank, the identity of the person who is to receive payment, and the legality of the document. A teller also must make sure that the written and numerical amounts agree and that the account has sufficient funds to cover the check. The teller then must carefully count cash to avoid errors. Sometimes a customer withdraws money in the form of a cashier's check, which the teller prepares and verifies. When accepting a deposit, tellers must check the accuracy of the deposit slip before processing the transaction.

Prior to starting their shifts, tellers receive and count an amount of working cash for their drawers. A supervisor—usually the head teller—verifies this amount. Tellers use this cash for payments during the day and are responsible for its safe and accurate handling. Before leaving, tellers count their cash on hand, list the currency-received tickets on a balance sheet, make sure that the accounts balance, and sort checks and deposit slips. Over the course of a workday, tellers also may process numerous mail transactions. Some tellers replenish their cash drawers and corroborate deposits and payments to automated teller machines (ATMs).

In most banks, head tellers are responsible for the teller line. They set work schedules, ensure that the proper procedures are adhered to, and act as a mentor to less experienced tellers. In addition, head tellers may perform the typical duties of a teller, as needed, and may deal with the more difficult customer problems. They may access the vault, ensure that the correct cash balance is in the vault, and oversee large cash transactions. Technology continues to play a large role in the job duties of all tellers. In most banks, for example, tellers use computer terminals to record deposits and withdrawals. These terminals often give tellers quick access to detailed information on customer accounts. Tellers can use this information to tailor the bank's services to fit a customer's needs or to recommend an appropriate bank product or service.

As banks begin to offer more and increasingly complex financial services, tellers are being trained to identify sales opportunities. This task requires them to learn about the various financial products and services the bank offers so that they can briefly explain them to customers and refer interested customers to appropriate specialized sales personnel. In addition, tellers in many banks are being cross-trained to perform some of the functions of customer service representatives. (Customer service representatives are discussed separately in another section of the Handbook.)