Legal analysis: the signature or seal of the labor contract is invalid. What a contract needs is the signatures or seals of both parties. Signature and seal have the same legal effect. But if it is a legal person, it is best to have a legal person seal. If the unit only seals and does not sign, as long as the legal representative of the unit performs his duties, that is, signs on behalf of the unit, rather than concluding a contract for his own affairs in his own name, then the contract is valid for the unit. If the contract held by the company is not signed and sealed, it is a case of not signing the contract. Although the employer can demand double the salary of the unsigned contract according to the law, the employer can sign and seal the contract that the employee has signed at any time, which makes it impossible for the employee to provide evidence.

Legal basis: Article 16 of People's Republic of China (PRC) Labor Contract Law shall come into effect after the employer and the employee reach an agreement through consultation, and the text of the labor contract shall be signed or sealed by both the employer and the employee. The text of the labor contract is held by the employer and the employee respectively.