Legal analysis: For a contract concluded in the form of a contract, if one party has performed its main obligations and the other party accepts it before signing or sealing, the contract is established. Even if the contract is not signed or stamped, the contract is legally established and is of course valid.

Legal basis: Article 490 of the "People's Republic of China and Civil Code"

If the parties conclude a contract in the form of a contract, both parties shall sign, seal or The contract is formed when the fingerprint is pressed. Before signing, sealing or fingerprinting, one party has performed its main obligations and the contract is established when the other party accepts it. Laws and administrative regulations stipulate or the parties agree that a contract should be concluded in written form. If the parties do not use written form but one party has performed its main obligations and the other party accepts it, the contract is established.