You can sign and submit a written statement appointing the person, or use our standard form SSA-1696, Appointment of Representative. SSS Authorization Letter is a document for authorizing an individual on your behalf to transact with the Social Security System.Regular class attendance is important, as is keeping up with your academic work. Don't be afraid to ask for help, whether academic or personal. Authorization Letter (1 copy). BIR, Post Office, SSS,. (a) If Authorized Representative - Authorization Letter.