You must sign your power of attorney in front of two witnesses for it to be enforceable in court. The power of attorney must be signed by the witnesses as well. The witnesses cannot include the attorney, their spouse or partner, your spouse, partner, child, or a person you treat as your kid, a person whose property is subject to guardianship or who has a guardian of the person, a person under the age of 18, or anybody who is under the care of another person.