Right after you and your agent have signed the documents, the durable powers of attorney take effect until they are revoked by the principal. The document is terminated at the death of the principal. Durable powers of attorney are named that way because no additional corrections to the documents are necessary once the principal becomes mentally incapacitated. In the United States, the word attorney is commonly used to refer to them. There are however many types of power of attorney depending on the nature of the contract, the scope of the power and the period that it is valid. The most common is of course the general power of attorney which authorizes the agent to act on your behalf and to represent you in dealings and other matters. The principal can also choose to appoint an agent or the attorney in fact (the person to whom the power of attorney is given to) to be his or her representative when they become ill. Some, in fact, appoint people to act on their stead while they are in the hospital and to make any medical decisions in their stead like when they need to pull the plug in case of a comatose. Still, many of those who are given the power of attorney are lawyers, often family lawyers who are trusted to deal with a wide range of things. When you are given the power of attorney, a person is authorizing you to act on their behalf in personal and business matters that have legal issues. They can sign your documents and decide for you while you are away or incapable of making decisions yourself. There are situations when the attorney-in-fact could be challenged. The principal should be prepared in case the power of attorney is confronted. It would help to have a video document stating with the principal stating the power of attorney or have several witnesses present to testify that the principal is mentally and psychologically competent when the document was signed. Because of its seemingly unlimited nature, the general power must be considered thoroughly before it is given to another person. It is advised that this type of power be used sparingly because it is prone to abuse and misuse of power by the agent. 2. Limited - This document, in contrast to the general type, authorizes the agent to make decisions for the principal on particular affairs for a limited time.