The personal seal on the contract is invalid. The official seal or contract seal can be used to sign a contract. When a natural person concludes a contract, the natural person who concludes the contract generally has to sign or seal it; When a legal person or other organization concludes a contract, it is generally signed by the legal representative of the legal person or the person in charge of other organizations or stamped with the official seal of the unit. In reality, there are many kinds of official seals of legal persons and other organizations, including special seals for contracts, special seals for finance, administrative seals and official seals of various departments. Generally speaking, both the special contract seal and the administrative seal can be used as the contract seal. As for the effectiveness of the special financial seal and the official seal of each department, it depends on the specific situation. If only financial issues such as debt amount (inter-enterprise statement) are proved, then the financial seal is also valid. Article 490 of the Civil Code If the parties conclude a contract in the form of a contract, the contract is 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. 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.

Legal objectivity:

People's Republic of China (PRC) Contract Law Article 35 Place of Formation of a Written Contract Where the parties conclude a contract in the form of a contract, the place where the parties sign or seal is the place of formation of the contract.