1. Not stamped, but the labor contract signed by both parties can be valid; If there is no signature or seal of both parties, the contract is invalid. The seal of the employer is not a necessary condition for the labor contract to take effect. In the absence of special agreement, the labor contract can take effect after being signed by both parties. A labor contract shall be reached through consultation between the employer and the employee, and shall come into effect after the text of the labor contract is signed or sealed by the employer and the employee.

2. Legal basis: Article 18 of People's Republic of China (PRC) Labor Law.

Labor contracts that violate laws and administrative regulations and labor contracts concluded by fraud or threat are invalid. The invalidity of a labor contract shall be confirmed by the labor dispute arbitration commission or the people's court, and the reasons for invalidity generally include the following aspects:

(1) The contract entity is unqualified. The employed party provides false academic qualifications, degrees and professional and technical qualification certificates, and the employing unit does not have recruitment qualifications. ;

(2) the contents of the contract are illegal, that is, the labor contract violates laws, regulations and good customs, or harms the national and social public interests. For example, making ice and counterfeit money. Labor contracts with illegal contents are not protected by law;

(3) The expression of meaning is untrue. A labor contract is the product of consensus reached by both parties and should be the true expression of the parties' intentions. Labor contracts concluded by means of fraud, threats, etc. It is against the true meaning of one party and therefore invalid;

(4) The contract form is illegal. This means that the labor contract is not in written form, the parties have not actually fulfilled their main obligations, or the labor contract that should be authenticated according to law or at the request of the parties has not been authenticated. Under normal circumstances, as long as the parties take remedial measures to legalize the contract formally, the contract can be considered valid.

Second, is it valid to stamp only the official seal on the contract?

According to the relevant laws and regulations, if the parties conclude a contract in the form of a contract, the contract shall be established when both parties sign or seal it. As far as the parties are concerned, they are nothing more than natural persons, legal persons and other organizations. When a natural person concludes a contract, it is generally signed or sealed by the natural person who concludes the contract. 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. The relevant laws and regulations do not clearly stipulate what chapter legal persons and other organizations should stamp. 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.