Gift and Debit Cards (Visa and Mastercard) To register your card for online use, locate the issuer's 800 number or web address. You'll find this information on the back of the Visa card or in a leaflet that comes with the card. Call the telephone number or access the website to get started. You'll need to provide the card code and card security number, as well as your personal information, including your name, address and telephone number. Use the same format for your personal information that you plan to use when making your online purchases. This is important as we check to verify that the information matches.