legal ground
Article 545 of the Civil Code
A creditor may assign all or part of its creditor's rights to a third party, except in any of the following circumstances:
(a) according to the nature of the creditor's rights shall not be transferred;
(two) according to the agreement of the parties shall not be transferred;
(3) It shall not be transferred according to law.
Article 55 1
Where the debtor transfers all or part of its debts to a third party, it shall obtain the consent of the creditor.
The debtor or a third party may urge the creditor to give consent within a reasonable time. If the creditor fails to express it, it shall be deemed as disagreement.
Article 555
With the consent of the other party, one party may transfer its rights and obligations in the contract to a third party.