Hello, I am a credit card user of Bank of China. The credit limit is the maximum overdraft limit in overdraft card, and the bill amount is the consumption amount. For example, the credit line is 20,000 (the maximum overdraft is 20,000), and you spent 5,000. The bill will show the credit line 15000 yuan, the bill amount is 5000 yuan, or the balance is 5000 yuan. If you deposit 1000 yuan in your card and spend money in 500 yuan, the bill shows that the credit line is 20000 (overdraft line is 20000), the bill amount is 500, and the balance is negative 500 (-500). If there is cash in the card, the balance is negative, the card is overdrawn, how much is overdrawn, and how much is displayed. I have thrown away all the bills, so there may be some mistakes in the explanation.