The Power of Attorney Rules for Witnesses for a Signing

A power of attorney can give the person you name as your agent the ability to access your bank account, make medical decisions for you or accomplish other tasks. State laws vary, but if your power of attorney is not properly witnessed and signed, it may not be accepted by others and won’t actually give your agent the authority you intended.

You must be mentally competent to sign a power of attorney, meaning you must know what you are doing and appreciate the legal effect of your signature. When someone witnesses your signature, he can later testify that you were competent at the time you signed. Without a witness, someone could question the validity of the document, particularly in cases where the person signing the power of attorney has periods of incompetence due to illness.

Where witnesses are required, you must generally sign the document or acknowledge your signature in the presence of the witnesses. This means that the witnesses must be physically present and watch as you sign the document.

Not everyone can act as a witness. In most situations, your witnesses must be mentally competent and must be at least 18 years old. Your state may require the witnesses to be “disinterested” in your power of attorney, which means your witnesses do not stand to gain from the power of attorney.

Some powers of attorney must be notarized, with or without witnesses. A notary’s purpose is to verify, through photo identification, that you are who you say you are. Often, notaries can also administer oaths.

​Read more​: Does Getting a Document Notarized Cost Money?

Some powers of attorney give the agent named in the document the power to access your bank account or make financial decisions, such as where to invest money and what money can be spent on. A witness may authenticate your power of attorney, adding an extra level of validation that could encourage your financial institution to accept the power of attorney.

Some states require witnesses or notarization for certain financial powers of attorney. For example, Washington requires notarization for powers of attorney that grant an agent the power to buy, sell or mortgage real property.

​Read more​: Can a Power of Attorney Get a Home Loan?

Health care powers of attorney give someone the right to make important decisions about a person's medical care. These can often be life-or-death decisions about medication, surgery, treatment options and end-of-life care.

State laws also vary regarding health care powers of attorney. For example, Alaska requires such powers of attorney to be notarized or witnessed by two witnesses, neither of which can be the agent, and only one witness can be related to the person granting the power of attorney.

Since a health care power of attorney gives an agent authority to make important health care decisions, including end-of-life care, a health care provider may want the added confirmation from witnesses or a notary.