1. Handle with the main card: When handling the main credit card, you can apply for a supplementary credit card together with the application form, and fill in the ID card information of the supplementary credit card holder.

2. Handling after the issuance of the main card: After the issuance of the main card, the cardholder of the main card must fill in the application form for handling the secondary card at the service outlet of the corresponding bank, provide the credit card number of the main card, and then submit the ID card information of the cardholder of the secondary card to the bank for handling.