Yes, the parties to the contract change the subject matter of the main contract through negotiation and supplementary agreement, which is also the embodiment of autonomy of will and free agreement. As long as the subject matter of the contract change is legal, the law does not interfere with the free change of the parties to the contract. If the contract change needs approval or registration, it can be handled according to legal procedures.

Legal analysis

Both parties can sign a supplementary agreement to the original contract after negotiation and attach it to the original contract for preservation. The supplementary agreement is an integral part of the contract and has the same effect as the original contract. You can also sign a new contract, and the original contract will be invalid. After the contract is signed, if it needs to be revised, it should ask the other party to amend it in time and inform the other party of the relevant amendments. In case of extra expenses, both parties can sign a supplementary agreement through consultation to modify the original contract. A supplementary agreement to a contract refers to an agreement reached by the parties without agreement or unclear agreement on the contents of the contract. Under normal circumstances, in the process of signing the contract, or after signing the contract, if the relevant terms are supplemented or added, it is necessary to sign a supplementary agreement to the contract. Signing a supplementary agreement can modify the terms of the original agreement. A supplementary agreement is a supplement or change to the original contract. Generally, it should be clearly stipulated that if the terms of the supplementary agreement are inconsistent or conflict with the original contract, the supplementary agreement shall prevail. However, if the original contract terms clearly indicate that they cannot be changed, the changes to the terms in the supplementary agreement have no legal effect. In case of conflict between the supplementary contract and the main contract, the terms agreed later shall prevail. Where laws and administrative regulations stipulate that the alteration of a contract shall go through the formalities of approval and registration, such provisions shall prevail. If the contents of the contract change are not clear, and the parties have not clearly agreed on the contents of the contract change, it is presumed that it has not been changed. If the parties enter into a contract in the form of a contract, the contract shall be established when the parties sign, seal or press their fingerprints. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it. Generally speaking, a contract is valid as long as it is the true intention of both parties.

legal ground

People's Republic of China (PRC) Civil Code

Article 119 A legally established contract is legally binding on the parties.

Article 543 The parties may modify the contract through consultation.