This section explains how a person, called the principal, can change a power of attorney. They can do this either by following the existing rules in the document or by creating a new document the same way the original was made. Additionally, anyone who doesn't know about these changes, like the person acting under the power of attorney or a third party, isn't responsible for actions taken without knowledge of the changes.

This law explains how a person (called the principal) can cancel a power of attorney, which is a legal document giving someone else authority to act on their behalf. First, they can revoke it by following any specific instructions outlined in the power of attorney document. Alternatively, they can cancel it through a written document, regardless of any terms in the power of attorney. Additionally, anyone acting as the representative (attorney-in-fact) or any third party involved is not responsible for actions taken without knowledge of the cancellation, as outlined in another set of laws starting with Section 4300.

This law explains when a power of attorney ends. It can end based on terms in the document, if what the power of attorney was for is no longer needed, if revoked, if the person who gave the power dies, or if the person with the power of attorney is removed, resigns, becomes mentally incapacitated, divorces the principal, or dies.

Also, if an attorney-in-fact or another person doesn't know the power has ended, they're not liable for their actions related to it, as long as they act without notice.

This law explains how you can revoke, or cancel, the authority given to someone under a power of attorney. First, you can follow any specific instructions already outlined in your power of attorney document. Second, you can revoke it any time by telling the person either verbally or in writing. Third, your legal representative can revoke it for you, but they need the court's approval to do so. If someone doesn't know that their authority has been revoked, they aren't responsible for any problems that might arise because of it, as long as they didn't know about the revocation.

If someone gives their spouse the power to act on their behalf through a power of attorney, and then gets divorced or their marriage is annulled, that power is automatically canceled.

However, if they get married to the former spouse again, the power of attorney gets restored automatically.

If someone gives another person the power to act for them through a nondurable power of attorney, this power stops when the person who gave it becomes unable to make their own decisions, unless the person acting or a third party didn't know about this incapacity. They're off the hook from any responsibility if they weren't aware. This rule can't be changed or limited by the power of attorney itself.