Mainly to protect cardholders’ card security. The payee is obliged to verify whether the signature on the card transaction slip is consistent with the cardholder's signature on the back of the credit card. If the signature on the card transaction slip is obviously different from that of the credit card, and the payee has no evidence to prove that the transaction was completed by the cardholder himself, the cardholder has the right to refuse to acknowledge the transaction and request the bank to stop payment. The receiving unit shall bear the corresponding losses on its own. One of the more common methods of credit card theft nowadays is to copy cards. However, they can generally only steal the information in the magnetic strip and the transaction password of the card through certain technical means, and it is difficult to imitate the cardholder's signature with a high degree of consistency. In this way, the loss of duplicate cards can be effectively avoided. If it is lost, unless the original card is recovered, it will be difficult to prove the cardholder's signature on the back, and payment cannot be refused on this basis.