What does it take to make a power of attorney valid?

People granting power of attorney must be mentally competent when they sign the power of attorney. The process of having witnesses sign the document helps to ensure that it's authentic and that those involved are competent. Also, their signatures need to be notarized, which also adds credibility. And if they have a lawyer prepare or review the documents, the lawyer's contact with them will also back up their competence at the time.

A power of attorney is valid in all states. The law of the state in which they reside at the time they sign a power of attorney will govern the powers and actions of the agent under that document. However, if they regularly have financial affairs in another state -- they own property there, or have a business interest -- it's not a bad idea to have a separate power of attorney prepared with the specific legal form used in that state.

• Can a power of attorney be changed?

As long as a someone is mentally competent, he can revoke a power of attorney at any time. Or he can maintain the power of attorney but change the agent. The person granting power of attorney should periodically revisit the document to determine whether it still meets his needs. If he wants to make a change, he should execute a new document rather than trying to make amendments on the old one.