If Party B does not sign, but one party has fulfilled its main obligations and the other party has accepted the performance of the other party, the contract is valid. Except for the above circumstances, this contract is invalid.
The conclusion of the contract:
The conclusion of a contract needs to reflect the true meaning of both parties, that is, both parties agree to conclude a contract and reach an agreement on the contents of the contract; Secondly, the contents of the contract should conform to the legal norms and must not violate the legal provisions.
The parties may conclude a contract by referring to the model texts of various contracts.
The validity of a contract means that the parties to the contract must perform their contractual obligations and may not change or cancel the legally binding force of the contract without authorization, that is, the legal effect. This "legal effect" does not mean that the contract itself is a law, but that because the will of the parties to the contract conforms to the will of the state and social interests, the state entrusts the will of the parties to the contract with binding force, requiring them to strictly perform the contract, otherwise relying on the coercive force of the state, requiring them to perform the contract and bear the liability for breach of contract.
The specific performance is as follows:
1, the general binding force of the contract on the parties. A legally established contract is legally binding on the parties. The parties shall perform their obligations as agreed, and shall not alter or terminate the contract without authorization.
2. Validity of the contract. A legally established contract shall take effect upon its establishment. The validity of a contract is reflected in the legal effect produced by the conclusion of a contract by two parties. The validity of each contract is specific, and the validity of each contract is different.
Legal basis:
People's Republic of China (PRC) Civil Code
Article 490 Where the parties conclude a contract in the form of a contract, the contract is formed when the parties sign, seal or fingerprint it. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it. A contract shall be concluded in written form as stipulated by laws, administrative regulations or agreed by the parties. If the parties do not do this in writing, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.