Federally authorized practitioners are able to afford clients the benefit of the confidentiality privilege for US tax advice that is otherwise available to attorneys under common law.
The confidentiality privilege is restricted to tax advice, and not items in an original tax return, provided that it is in non-criminal proceedings and not related to tax shelters. It is also limited only to the IRS and cannot be used to protect information from disclosure to other US government agencies.
A federally authorized practitioner includes an attorney, a CPA, and an enrolled agent, all classified as individuals who are authorised to practice before the IRS.