Visa primary and secondary credit cards are not interchangeable. The main credit card and the secondary card are in a subordinate relationship. The secondary card is under the name of the primary card, has the same function, and is the only account.

A credit card supplementary card is an supplementary card. The main credit card and the supplementary card can enjoy the credit limit of the main card. The consumption records are unified into the main card bill, and the main cardholder pays the outstanding balance. . For example, if the credit limit of the primary credit card is 20,000 yuan, and the credit limit of the secondary card is 5,000 yuan, then the available credit limit of the primary and secondary credit cards for the month will be 15,000 yuan.

Since the primary and secondary credit cards enjoy the same credit limit, the cardholders of the two credit cards may not know how much the other has spent during use, so they should communicate frequently to avoid exceeding the credit limit.