According to the regulations of Shanghai Bank, to apply for a credit card, you need to provide a work certificate as one of the application materials. The work certificate can prove the applicant's work status and income, and it is one of the important basis for banks to evaluate the credit status of credit card applicants. The work certificate usually includes the employment certificate, payroll or bank statement issued by the unit. By providing proof of work, the bank can better evaluate the repayment ability and credit risk of the applicant, so as to decide whether to approve the credit card application.