if you want to check the card number of the supplementary card of a credit card, the method is actually similar to that of the main card number of the credit card. In fact, the card face of each credit card is generally marked with a detailed card number, so customers can know the specific card number of this card directly (usually 16 digits).
if the customer doesn't have the card with him and needs to know the card number at present, he can also log in to the personal online banking, mobile banking client or credit card APP of the issuing bank, select the card he wants to inquire from the card list in the personal account interface, and click to enter the details page to find the specific card number. Some may hide some card numbers. In this regard, customers can generally expand all card numbers by entering the information management page.
of course, customers can also call the customer service phone of the issuing bank directly, transfer the manual service and ask the customer service staff of the bank. The customer service staff will inform the customer of the specific card number after verifying that the customer identity information is correct. Or the customer can go to the nearby branch counter to find the staff to inquire with his personal valid ID.