At Yahoo!, we are always looking for secure ways to help you verify your identity and recover your password. If you have used a credit card to subscribe to or purchase Yahoo! premium services, we may be able to verify your identity using that credit card.
In order to protect your account from intruders, we require that you enter all the digits of your credit card number.
You should always ensure that you are on a legitimate Yahoo! site before entering any personal information, including your credit card number.