What does it mean that the Sichuan tax payment page cannot find a valid social security code?

According to relevant data, the social security card code refers to the card number of the social security card, which is below the bar code in the lower right corner of the front of the social security card. The social security card code is the serial number automatically formed when making the social security card, and you don't need to fill it in yourself. The card number represents the identity information of the cardholder and is the only ID number of the insured. Insured persons can call social security telephone number 12333, or bring their ID cards to social security service outlets to check the number of personal social security cards.