If the agreement in the contract must be stamped with the official seal and signed by the legal person, the unsigned contract has no legal effect. If there is no express provision, it is also legal and effective. When signing a contract, both parties need to sign it on the condition of consensus and equality, and neither party can coerce others to sign the contract. Effective elements of the contract: 1, meaning is true. 2, does not violate the law or social public interests. 3. The subject matter of the contract must be definite and possible. The subject matter of a contract determines the quality and quantity of contractual rights and obligations. Without it, the contract will lose its purpose and positive significance and should be invalid. The possibility of the subject matter of the contract means that the contract payment may be realized. The determination of the subject matter of the contract means that the subject matter of the contract is determined or can be determined from the beginning. 4. The actor has corresponding capacity for civil conduct.

legal ground

Article 490 of the Civil Code of People's Republic of China (PRC): If the parties conclude a contract in the form of a contract, the contract is concluded 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.