The reason why the Bank of Communications credit card requires a supplementary social security provident fund certificate is because its risk control mechanism needs to further verify the applicant's income and assets to ensure the credit card applicant's repayment ability and credit status. Social security and provident funds are one of the sources of personal income and assets. Providing these certificates allows banks to better assess the applicant's repayment ability and helps reduce the risk of non-performing loans. In addition, providing social security provident fund certificates can also improve the credit score of credit card applicants, because these certificates can prove the applicant's income and asset stability, which is conducive to improving the personal credit record and credit score, thereby obtaining a higher credit limit and more Discounted credit card services. Therefore, providing proof of social security provident funds is a risk control measure taken by banks to protect their own interests and the interests of customers.