A.R.S. § 14-6205: Designation of agent; authority; termination

A. By a writing signed by all parties, the parties may designate as an agent for all of the parties on the account a person who is not a party to the account.

B. Unless the terms of an agency designation provide that the authority of the agent terminates on disability or incapacity of a party, the agent's authority survives disability and incapacity. The agent may act for a party with disabilities or incapacitated party until the authority of the agent is terminated. The death of the sole party or last surviving party terminates the authority of an agent.