A user of credit card is published the chart after the approval of a supplier (often a general bank, but sometimes of a captive bank created to publish a particular mark of credit card, as (banks of Centurion of American Express), in which they will be able to make purchases starting from the traders supporting that the credit card until A prenegotiated the authorization of overdraft.

When a purchase is made, the user of credit card indicates his assent to the wages, usually by signing a receipt with a disc of the details of chart and by indicating the quantity to be paid. More recently, the electronic systems of checking made it possible to the traders (employing a band of material magnetized on the chart holding the information in a similar way on the magnetic tape or a diskette) to check that the chart is valid and the customer of credit card has the sufficient credit to cover the purchase in some in the second place, making it possible the checking to occur at the period of the purchase.

Some services can be paid for by telephone by the credit card simply by quoting the number of relief in relief on the chart (the number of credit card), and they can be employed in a similar way to pay purchases of the suppliers on line. Each month, the user of credit card is sent a report/ratio indicating the purchases undertaken with the chart, and all it of the sum due. The holder of chart must then pay a proportion minimum of the invoice on a which had date, and can choose to pay more or to pay sum due whole indeed. The supplier of credit charges the interest on sum due (typically ata rate much higher than the majority of the other forms of debt). The transmitters of credit card can draw aside from the expenses of interest if balance is entirely paid each month, which makes it possible the credit card to be used as form of revolving credit, or they can choose to rather apply all the payments towards recent than preceding debt. The interest rates of interest can change chart with the chart considerably, and the interest rate of interest on a particular chart can jump clearly on if the user of chart is late with a payment this chart or any other instrument of credit. While the rates and the limits change, of the services were installed while allowing users to calculate the saving available by commutating the chart, which can be considerable if there is a great exceptional balance (see the external bonds for some services on line). Since the profit margins in the industry of credit card can be completely high, the suppliers of credit often offer incentives such as miles of frequent traveller, certificate-premiums, or the money back cash (in general 1 percent) to attract customers with their program.