Legal analysis: the intermediary contract is invalid without signature. The content of the intermediary contract is the service contract agreed by the intermediary and the buyer and the seller, so it must be signed by the intermediary. If the intermediary does not sign, the validity of this contract does not exist, so if there is a legal dispute in the future, there is no way to protect the legitimate rights and interests of the parties to this intermediary contract.

Legal basis: Civil Code of People's Republic of China (PRC).

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.

Article 961 An intermediary contract is a contract in which the intermediary reports to the client the opportunity to conclude a contract or provides media services for concluding a contract, and the client pays the remuneration.