It is relatively easy to apply for a credit card sub-card, just need to prepare some necessary materials. Let's take a look at what information we need to prepare for the secondary card.

First, you need your own identification documents, such as your ID card or passport. These documents need to be provided because the identity of the main card holder needs to be verified when handling the secondary card.

Secondly, you need to provide relevant information about the applicant of the secondary card, such as name, age, gender, contact information, etc. This information can be submitted by filling in the application form.

Finally, you need to provide some information about the main card holder, such as the name of the main card holder, credit card account number, marital status, etc. This is because the rights and restrictions of the secondary card depend on the account information of the main card holder.

In short, it doesn't need much preparation to handle the credit card sub-card, just provide the necessary identification documents, applicant information and the information of the main card holder. I believe that through the above introduction, you will know more clearly how to handle the credit card sub-card.