A letter with legal documents allowing a next of kin to transact on one's behalf.
To Whom It May Concern,
From here on, my brother Carmine Peters will be handling my business and financial affairs. I would like to make this official and legal. Please see the attached Power of Attorney documents which are notarized. Carmine is allowed to withdraw and transact money from all my accounts while I am infirmed. You may call me at 555-788-800 for any concerns.