A lawyer who is the sole lawyer signatory on an attorney trust account may designate in an instrument acceptable to the depository for the trust account, a successor signatory, who must be a member of the bar in good standing and admitted to the practice of law in Iowa, and whose authority must become effective upon the occurrence of an event or events described in the instrument. The event or events described in the instrument may include death, disappearance, abandonment of law practice, temporary or permanent incapacity, suspension, or disbarment.
Cli. Trust Acc. R. 45.11