Legal analysis: Legal. According to the provisions of the "People's Republic of China and the Civil Code", the performance of debts should be based on the contract and the obligations such as notification and assistance should be fulfilled. Credit card arrears are debt liabilities and collection is legal.

Legal basis: Article 509 of the "People's Republic of China and Civil Code" The parties shall fully perform their obligations in accordance with the agreement. The parties shall abide by the principle of good faith and perform obligations such as notification, assistance, and confidentiality in accordance with the nature, purpose and transaction practices of the contract.