If you want to enter the payment account number on the online payment page of CCB, you must enter the card number of the credit card. If it is the first time to pay online with this credit card, you should generally enter the validity period and CVV2/CVC verification code on the back of the card when paying. There will also be SMS verification code. The card number and expiration date are engraved on the front of the card. If the expiration date is 05/20, it means it will expire in May 2020. Just enter 0520 on the web page. The CVV2/CVC code is the three digits to the right of the signature on the back of the card.