The principal usually determines when the POA begins and ends and outlines it in the form. However, suppose the start and end dates are not specified in the form. In that case, the date it is signed is considered the POA real estate start date. It will remain valid until the principal chooses to revoke it, becomes incapacitated (if it is non-durable), or the principal or agent dies. A court order may also terminate the real estate power of attorney.