Can Someone With the Power of Attorney Change Someone Else's Will Before He Is Dead?

A power of attorney grants an agent, sometimes called an "attorney-in-fact," the authority to act on behalf of the grantor, or "principal." Power of attorney documents may grant an attorney-in-fact limited authority, such as the authority to pay bills, or more general authority, such as the authority to manage the principal's finances. However, a power of attorney cannot give an agent the authority to change a will. In fact, the only person with the authority to change a will is the person who made it.

Although power of attorney documents may grant very broad authority, they cannot grant a right to change a principal's will before his death. An attorney-in-fact's powers may include the ability to buy and sell real estate and to access the principal's bank accounts. An attorney-in-fact may also have the power to make health care decisions if the principal becomes incapacitated. Although the specific laws vary among states, certain formalities are required when wills are executed or changed.

Read More: Can You Change a Will Using Power of Attorney?

A person who makes a will -- the "testator" -- is required to follow certain formalities when making a will. These formalities are required when changing a will as well. For example, testators must be fully aware of the implications of making a will; they are also required to have the capacity to recognize family members and understand the extent of their property. Generally, wills must be written by the testator, attested by at least two witnesses and signed by the testator.

Testators may change a will by executing a codicil or revoke an entire will by making a new one. Generally, the same formalities are required when a will is changed, meaning that codicils typically require witnesses and the testator's own signature. No one else is authorized to revoke or change a will for a testator during his lifetime or after. A testator may not delegate the power to change his will to someone else, including an attorney-in-fact. Some states allow someone else to sign for the testator if the testator is incapable of signing for himself; however, it must be at his direction and in his presence.

If someone other than the testator changes a will, the testator's family members may challenge the will's validity in a probate court. If a probate court decides there is sufficient evidence to suggest the testator's will was changed by someone else, the entire will may be declared invalid. When a will is declared invalid, a testator's property is generally distributed according to the laws of the state where the testator lived.