Your status with this application. The PHL City ID provides a secure and affordable photo identification card for anyone living in Philadelphia, age 13 and older.Authorization Letter (PL ONLY). To get a PHL City ID, applicants must prove their identity and residency in Philadelphia. By signing this form, you allow us to share your protected health information (PHI) with the persons and organizations you put on this form. A CAF number is a unique ninedigit identification number and is assigned the first time you file a third party authorization with IRS. Mail completed form in the return envelope provided or fax the form to the county assistance office with: • Proof of all household members' income from work. Children traveling alone can't check in online or at the kiosk. Instructions for completing the Third Party Letter of Authorization (LOA). Need help downloading or filling forms?