As long as you are not incapacitated, you can revoke a power of attorney at any time. The only thing required to accomplish this is to send a letter to your agent notifying him or her that the appointment has been revoked. A copy of this letter should be sent to any person or institution that received notice of the original power of attorneys, such as your doctor or your bank. This step is necessary because individuals and institutions may continue to rely on the power of attorney without notice that it has been revoked.