According to the information provided in the question, if the Bank of Communications credit card limit is 3,000 yuan, the amount that needs to be repaid after 3 years of overdue is the original debt plus interest, late payment fees and liquidated damages. You can apply for the minimum repayment amount, but you still need to pay the remaining outstanding balance and corresponding fees.

The specific answers are as follows:

1. How much money do you need to pay back after 3 years of overdue payment?

The amount that needs to be repaid after 3 years of overdue includes the original arrears, interest, late fees and liquidated damages.

2. Detailed description:

- Original debt: The original debt refers to the outstanding amount of the credit card limit of 3,000 yuan.

- Interest: According to the interest calculation standards of Bank of Communications credit cards, interest is calculated based on the overdue time.

- Late payment fees: When overdue, late payment fees will be calculated according to a certain ratio. The specific ratio can be obtained by consulting the Bank of Communications Credit Card Service Agreement.

- Liquidated damages: If the cardholder is overdue for too long, credit card liquidated damages may be triggered. The specific amount can be obtained by checking the credit card service agreement or consulting bank customer service.

3. Summary:

The amount that needs to be repaid after 3 years of overdue includes the original arrears, interest, late fees and liquidated damages. The specific amount is calculated according to the provisions of the credit card service agreement.

Extended information:

Overdue credit card repayments will affect the cardholder's credit record and may be restricted by the bank, affecting future borrowing ability. Therefore, it is recommended that cardholders contact the bank as soon as possible to understand the specific situation of overdue repayment and take corresponding repayment measures to avoid further fees and credit impacts.

Please note that the above answers are based on the relevant regulations of credit cards under general circumstances. For specific circumstances, you need to consult Bank of Communications credit card customer service or review relevant agreements and terms.

The above is the answer to the situation where the Bank of Communications credit card limit is 3,000 yuan and is overdue for 3 years.