A copy of the registered owner's valid U.S. State issued Driver License or Personal Identification Card or Federal Identification is required. Edit, sign, and share authorization letter harris county online.No need to install software, just go to DocHub, and sign up instantly and for free. First, email us a photocopy of your Texas authorization letter that you have already filed with the Texas Secretary of State office. Signature: Date: HOUSTON HEALTH DEPARTMENT. The Owner of Record may use this form to authorize a Third Party to process and pick up related items for motor vehicle transactions noted below.