For Transaction Privilege Tax License and Withholding Registration: If the ownership changes require a new Employer Identification. Congratulations on being selected as an Authorized Signatory for your company!Thank you for contacting PHX Customer Service. To start the application process, you can call us at 888-621-6880 (toll-free) or register an application online in Health-e-Arizona Plus. CHANGE IN EXISTING STATUTORY AGENT NAME ONLY – if the name only of the existing statutory agent listed in ACC records has changed, but a new. Authentication Code is 4-digit PIN code associated with your respective PHX. SIDA badge or ID Credential. Form Number, Document Name, Last Updated. The city of Phoenix. Contact Person – Attach a letter indicating the scope of authority the contact person will have regarding company operations.