CCB needs to supplement the income certificate when sending a text message with a credit card, which means that CCB needs you to provide more income proof materials to verify your income. This is because in the process of credit card application, banks need to evaluate the applicant's credit status, repayment ability and income to decide whether to approve the credit card application. Your income proof is insufficient or you can't prove that you have enough repayment ability, which will affect your credit card application result.