The sales contract is invalid if it is not stamped and effective, but it is not stamped, signed or fingerprinted. According to the relevant laws and regulations, if the parties conclude a contract in writing, unless otherwise provided by law, the contract shall be established and come into effect when both parties sign, seal or press their fingerprints.

legal ground

Article 490 of the Civil Code of People's Republic of China (PRC)

If the parties enter into a contract in the form of a contract, the contract shall be established when the parties sign, seal or press their fingerprints. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.

Article 502

A legally established contract shall come into force upon its establishment, except as otherwise provided by law or agreed by the parties.

In accordance with the provisions of laws and administrative regulations, if the contract should go through the approval procedures, such provisions shall prevail. If the failure to go through the formalities such as approval affects the effectiveness of the contract, it will not affect the performance of the obligation clauses such as approval and the effectiveness of relevant clauses in the contract. If the party that should go through the formalities for approval fails to perform its obligations, the other party may require it to bear the responsibility for violating its obligations.

The modification, assignment and dissolution of a contract shall be subject to the provisions of laws and administrative regulations, and the provisions of the preceding paragraph shall apply and shall be subject to approval.