Final answer:
It's not permissible to sign documents on another's behalf without a power of attorney, which can lead to legal issues like forgery or fraud.
Step-by-step explanation:
It is generally not permissible for someone to sign legal documents on behalf of another person unless they have been granted the authority to do so, typically through a power of attorney. Having someone else sign documents without proper authorization could lead to legal issues, such as questions of validity and potential allegations of forgery or fraud. In the scenario described, unless you have been granted a power of attorney by Henry, signing documents in his stead would not be allowed.