According to the American Bar Association, the agent can sign the agent's name as attorney-in-fact for the represented party. Another alternative for the agent is to sign the represented party's name, and then add the agent's name under power of attorney.
For example, if Bill Clinton gave Hillary Clinton a power of attorney over his affairs, Hillary could sign either Hillary Clinton as attorney-in fact for Bill Clinton, or she could sign Bill Clinton, by Hillary Clinton under power of attorney. The scope of a power of attorney is limited to powers the represented party grants to the agent. These powers can be specific or general. If the power of attorney allows the agent to buy a house for the represented party, then the agent cannot make medical decisions for the represented party. If the agent acts outside the scope of the power of attorney, he may be personally liable for those actions, notes the American Bar Association.
Power of attorney is a convenient way to handle affairs in case of illness or disability. Most states have a durable power of attorney that does not expire or need to be renewed. This durable power of attorney can be revoked by giving written notice to the agent, according to the American Bar Association.