1. If the parties authorize a third person to sign on their behalf, the contract is valid;

2. If the person signing on behalf of the company has no power of attorney, exceeds the power of attorney or signs on behalf of the company after the power of attorney is terminated, the effectiveness of the act of signing on behalf of the company is uncertain. The principal shall bear civil liability for the signature, although the party concerned is unaware of it, but it is ratified by the principal afterwards; Without ratification, the actor who signed it shall bear civil liability;

3. If the signer (i.e. the trustee or agent) is entrusted by the signer (i.e. the principal or the principal) to sign on his behalf, or if the signer knows that others are signing in his own name and does not deny it, the signature is valid and the signer shall bear legal responsibility;

4. If a third party signs a contract in its name without the authorization of the parties, this contract has no legal effect on the parties, and all the consequences arising therefrom shall be borne by the third party who uses its name.