Legal analysis: 1. Apparent assignment, that is, when the creditor notifies the debtor of the assignment of the creditor's rights, even if the assignment contract is not established or does not take effect, the debtor's performance to the assignee based on the trust in the notification fact is still valid. In the case of assignment by estoppel, the creditor has no right to claim against the debtor after the debtor pays off the debt to the assignee. 2. The debtor colludes with the assignee in bad faith. For example, the transferee and the transferor signed a contract to pay the transfer consideration by installments, stipulating that within a few days after paying the initial consideration, the transferor would serve the debtor with a notice of assignment of creditor's rights, and the debtor would immediately perform all the debts to the transferee, and then the transferee would disappear, which would harm the interests of the transferor.
Legal basis: Article 67 of the Civil Code of People's Republic of China (PRC).
Where a legal person is merged, its rights and obligations shall be enjoyed and assumed by the merged legal person. Where a legal person is divided, its rights and obligations shall be jointly claimed by the divided legal person, unless otherwise agreed by the creditor and the debtor.