The credit limits of two credit cards in the same bank are shared, and the credit limits of the two cards are subject to the one with the higher credit limit. For example, the user's A card has a quota of 20,000 and the B card has a quota of 30,000, so the sum of the two cards is 30,000. When A card uses 20000 credit line, B card can only use 1000 credit line. When the B card uses more than 20,000 points, the A card has no points to use.