Legal Basis
Article 143 of the Civil Code of the People's Republic of China
Civil legal acts that meet the following conditions are valid:
(1) The actor has the corresponding capacity for civil conduct;
(2) The expression of intention is true;
(3) It does not violate the mandatory provisions of laws and administrative regulations, Do not violate public order and good customs.
Article 490
If the parties conclude a contract in the form of a contract, the contract shall be established when all parties sign, seal or fingerprint. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.