The credit limits of two credit cards of China Construction Bank are shared, but they cannot be repaid together, so they need to be repaid separately. Repayments are paid separately according to the card number, and not all of them can be paid to one credit card, so the system will not automatically allocate them to another. In this way, there will be multiple cards, which will lead to overpayment and the other credit card will not be paid. You can bind two credit cards to the savings card of CCB, and then transfer the repayment amount to the savings card, so that the two cards will automatically repay when they are due.