A debit card (also known as a bank card or check card) is a plastic card that provides the cardholder electronic access to his or her bank account(s) at a financial institution. Some cards have a stored value with which a payment is made, while most relay a message to the cardholder's bank to withdraw funds from a designated account in favor of the payee's designated bank account. The card can be used as an alternative payment method to cash when making purchases. In some cases, the primary account number is assigned exclusively for use on the Internet and there is no physical card.

In many countries, the use of debit cards has become so widespread that their volume has overtaken or entirely replaced cheques and, in some instances, cash transactions. The development of debit cards, unlike credit cards and charge cards, has generally been country specific resulting in a number of different systems around the world, which were often incompatible.
Unlike credit and charge cards, payments using a debit card are immediately transferred from the cardholder's designated bank account, instead of the them paying the money back at a later date.