Accountants, Attorneys, enrolled agents or other representatives from whom a taxpayer has requested assistance on tax problems submit inquiries to IRS. The third party expects a reply to the inquiries so that problems can be explained to the taxpayer. To authorize this third party reply, the representative may submit a Form 2848, Power of Attorney and Declaration of Representative (PDF), or Form 8821, Tax Information Authorization (PDF).

A CAF number is assigned to a tax practitioner when a Form 2848 or Form 8821 is filed. This number represents a file that contains information regarding the type of authorization that taxpayers have given representatives for the various modules within their accounts. If you are a tax practitioner who has previously been assigned a CAF number but cannot locate the number, call the Practitioner Priority Service, who will mail your CAF number to you.

References/Related Topics

• Instructions to Form 2848, Power of Attorney and Declaration of Representative (PDF)
• Publication 947, Practice Before the IRS and Power of Attorney
• Form 2848 in Spanish, Poder Legal y Declaracin del Representante (PDF)
• Form 2848 Instructions in Spanish Instrucciones para el Formulario 2848(SP) (PDF)