According to the authorization of the authorizer, signing on behalf of the authorizer is a legal act. This phenomenon is very common in real life. Some are trivial matters in daily life, and some are major economic activities and important matters, which the principal authorizes others to sign. For example, it is normal for the principal to hand over his or her ID card and authorization letter to the principal to pick up the express or even sign the contract. It is illegal to sign on behalf of others without authorization or authorization from the principal. In serious cases, you may also be held criminally responsible. For example, if a national civil servant signs an important request for instructions without the consent, approval, or authorization of the person with the authority to handle it, resulting in significant economic losses or casualties, he will be held criminally responsible.