legal analysis: if the parties conclude a contract in the form of a contract, the contract will be established when all 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.

Legal basis: Article 489 of the Civil Code of the People's Republic of China

promises to make immaterial changes to the contents of the offer, unless the offeror promptly objects or the offer indicates that it promises not to make any changes to the contents of the offer, the acceptance is valid, and the contents of the contract shall prevail.

article 49 when the parties conclude a contract in the form of a contract, the contract is formed when all 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 writing as stipulated by laws and administrative regulations or agreed by the parties. if the parties fail to do so in writing, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.