You may revoke the authority of the agent. n order to revoke, cancel, or end a power of attorney before it expires, the principal must sign a revocation of power of attorney and give a copy of the revocation to any person who might have or will possibly deal with the agent. Giving a copy of the revocation to people the former attorney-in-fact dealt with is to avoid an apparent authority situation.

A person has apparent authority as an agent when the principal, by his words or conduct (e.g., having granted power of attorney to former attorney-in-fact), leads a third person to reasonably believe that the person/agent has the authority that the agent appears to have, and the third person relies on this appearance of authority. The question of apparent authority is probably the most litigated question in agency law.

If a principal revokes a power of attorney that is recorded in the real estate records of a county, a revocation of that power of attorney should also be recorded in the real estate records.