It is not necessary to pay back the full amount. The following is a detailed explanation:

1. Overdue credit card repayment refers to failure to repay on time after the repayment date. If you simply fail to pay the full amount due on your credit card and choose to pay the minimum payment on your credit card, it can be considered overdue.

2. The minimum repayment amount is the minimum repayment requirement stipulated by the bank. Typically, the minimum payment is a fixed percentage of the amount due, usually a fraction of the amount due. If you only make the minimum payment, the remaining balance will be included in your next bill and interest charges will accrue.

3. Late repayment will have a negative impact on your personal credit record. Late payments will appear on your credit report, which can lead to difficulties applying for a loan or credit card in the future, or getting a loan with a higher interest rate.

To sum up, you do not have to pay the full amount of your credit card overdue, you only need to pay the minimum repayment amount. However, late repayments can have a negative impact on an individual's credit record, so it is recommended to repay on time to avoid overdue payments and a bad credit record.

Extended information:

Banks usually set the minimum repayment amount of a credit card as a certain proportion of the amount due, such as 5 or 10. Paying the minimum payment will prevent you from being late, but the remaining balance will incur high interest charges that will continue to accrue on your next bill.

If you encounter difficulties in paying the full amount due, it is recommended to pay as much as possible to reduce the accumulation of interest, and to repay in full before the next bill date. Banks often advise customers to pay off their credit card bills in full to avoid interest charges while maintaining a good credit history.

In addition, if you cannot repay on time due to special circumstances, you can contact the bank and explain the situation. Some banks may offer some flexible repayment arrangements, but the specifics may vary depending on bank policies.

Please note that the answers provided above may be based on general practices in the Chinese banking industry and may not be applicable to all situations. In specific cases, it is recommended to ensure that you communicate with your credit card issuer and follow their instructions.