This authorization letter appoints someone to act as the author's attorney-in-fact to represent them before the Social Security System. Fill in the name and address of the person or organization of where you want us to send the requested information.You must complete form SSA-11 (Request to be selected as payee) and show us documents to prove your identity. SSS Authorization Letter is a document for authorizing an individual on your behalf to transact with the Social Security System. Part 1: I want to give permission for someone to act as my authorized representative. SSS Authorization Letter is a document for authorizing an individual on your behalf to transact with the Social Security System. You may qualify for a Social Security Benefit Subtraction. Fill out this form in one (1) copy. 2. applicable. 3. 4. 5. 6. 7. See ACES Manual, SSP Chapter. When SSI benefits begin: Example: Client gets first SSI cash payment in October 2004.