1. Credit record is damaged: if it is overdue, it will be recorded by credit institutions, which will have a negative impact on future applications for loans, credit cards and other financial products.

2. High penalty interest: Late payment will trigger a high penalty interest, which will accumulate to the next billing cycle, making it more difficult to pay off the arrears.

3. Increase the overdue fee: the bank will charge the overdue fee, and the amount can be adjusted according to the specific situation.

4. Affect the borrowing ability: overdue records will affect the credit rating, reduce the borrowing ability, and make the future loan interest rate higher or impossible to borrow.

Summary: twelve days overdue will seriously affect personal credit record and borrowing ability, and increase penalty interest and overdue fee. It is recommended to avoid overdue credit cards and repay them in time.

Extended data:

In addition to the above effects, overdue credit cards may also lead to telephone harassment, collection actions, legal proceedings and drag down interpersonal relationships. In order to avoid the occurrence of overdue phenomenon, it is necessary to set reminders, control consumption, rationally plan the budget, and ensure that the minimum repayment amount is paid before the repayment deadline. If it is overdue, contact the credit card issuer immediately and make a repayment plan. Dealing with overdue problems in time will help to minimize the negative impact and restore a good credit record.

Note: The above answers are for reference only, and the specific situation may be different due to personal credit records, banking policies and other factors. For accurate information, please consult relevant professional institutions or banks.