The effective time of the contract modification agreement is the time when the agreement is established according to law. If the parties agree otherwise, their agreement shall prevail. According to the provisions of Article 502 of the Civil Code, a legally formed contract shall take effect from the time of its formation, unless otherwise provided by law or agreed by the parties. Where, in accordance with the provisions of laws and administrative regulations, a contract shall go through the formalities of approval, etc., such provisions shall apply. Failure to go through approval and other procedures that affect the effectiveness of the contract shall not affect the effectiveness of the obligation clauses in the contract such as performance of approval and relevant clauses. If the party who should go through the formalities of application for approval fails to perform its obligations, the other party may request it to bear the responsibility for breach of such obligations. In accordance with the provisions of laws and administrative regulations, the provisions of the preceding paragraph shall apply to the change, transfer, dissolution and other circumstances of a contract where approval and other formalities shall be handled.
 Legal basis: A contract established in accordance with the law in Article 502 of the Civil Code shall come into force upon its establishment, unless otherwise provided by law or agreed by the parties. Where, in accordance with the provisions of laws and administrative regulations, a contract shall go through the formalities of approval, etc., such provisions shall apply. Failure to go through approval and other procedures that affect the effectiveness of the contract shall not affect the effectiveness of the obligation clauses in the contract such as performance of approval and relevant clauses. If the party who should go through the formalities of application for approval fails to perform its obligations, the other party may request it to bear the responsibility for breach of such obligations. In accordance with the provisions of laws and administrative regulations, the provisions of the preceding paragraph shall apply to the change, transfer, dissolution and other circumstances of a contract where approval and other formalities shall be handled.