The reasons why the credit card balance cannot be checked:

1. If you are using an ATM machine to check, the credit card may be degaussed, or the credit card may not have the ATM machine query function enabled.

2. If the credit card statement has not been received, it cannot be queried.

Methods and steps for querying account balance and details:

1. Counter query: Bring your ID card and bank card to the bank counter for query;

2. ATM query: Insert the bank card into the ATM machine, enter the password, and click Query to query the balance and transaction details;

3. Online banking query: Log in to the bank's official website, click Online Banking Login, and fill in the correct information. The card number and password can also be logged in to check.