To pay any outstanding account invoices, or to update/provide credit card details for automated billing if you are not a bill-by-invoice customer:
Click the Billing link on the My Account menu, or the Billing button, or the Invoices link under the Billing section of the Overview page.
The Billing screen opens, showing your outstanding invoices at the top of the page. A credit card payment form is shown on the lower part of the page:
Type your credit card details into the form. All mandatory fields are marked with red asterisks. Once you have entered the card's details, click the Update and Store Information button to update the stored credit card details, or the Pay button to pay the invoice.