The cardholder’s signature on the back of the credit card. Most credit cards have a signature area written on the back. After the credit card holder applies for the credit card, he or she can sign his or her name on the card holder’s signature area on the back of the credit card. Therefore, the credit card application contract is written on the card holder’s signature area on the back of the credit card. Signature at the signature office. The advantage of signing when receiving a credit card is that it facilitates the cashier to check the signature when swiping the card for consumption, ensuring the safety of the card and protecting the security of personal information.