Centralized Authorization File (CAF) Number

A Centralized Authorization File (CAF) Number is a unique identifier issued by the Internal Revenue Service (IRS) to tax professionals authorized to represent taxpayers. This nine-digit ID is key for tax attorneys, Certified Public Accountants (CPAs), Enrolled Agents (EAs), and other authorized representatives, allowing them to access client tax information and act on their behalf with the IRS.

When a taxpayer authorizes a representative by completing and signing IRS Form 2848 (Power of Attorney and Declaration of Representative) or Form 8821 (Tax Information Authorization), the IRS assigns or links a CAF number to that representative. This number serves as a centralized record for all their authorizations and the specific tax matters they manage for clients. Rather than each new client requiring a separate number, the CAF number stays with the representative, streamlining IRS communications and case management.

The CAF number ensures efficient identification and tracking of authorized representatives in the IRS system. It protects taxpayers’ privacy by ensuring only properly authorized individuals can view sensitive tax details, while facilitating faster handling of inquiries and disputes.

Why the CAF Number Matters

• Streamlined IRS Communication: Quickly identifies authorized representatives to avoid delays.
• Enhanced Security: Controls access to confidential tax information.
• Simplified Case Management: Enables tax professionals to manage multiple clients efficiently.

Who Needs a CAF Number? Tax attorneys, CPAs, EAs, enrolled actuaries, and any individual appointed through Form 2848 or Form 8821 who regularly interacts with the IRS on a taxpayer’s behalf.

If a tax preparer only files returns without representing taxpayers in audits or disputes, a CAF number isn’t necessary.

Distinct Roles: CAF Number, Power of Attorney, and Tax Information Authorization

• Power of Attorney (Form 2848): Grants broad authority to act and represent taxpayers before the IRS.
• Tax Information Authorization (Form 8821): Allows access to tax information only, without representational powers.
• CAF Number: The IRS’s internal tracking ID tied to all authorized representatives and their submitted forms.

Obtaining a CAF Number
Taxpayers do not obtain a CAF number themselves. Instead, it’s automatically assigned by the IRS to tax professionals upon processing valid Form 2848 or Form 8821 submissions. If the professional already has a CAF number, it is reused for all subsequent clients.

Working Effectively with Your Authorized Representative:

• Choose qualified tax professionals such as CPAs, EAs, or attorneys.
• Understand and review authorization forms carefully.
• Specify authorization scope clearly in the forms.
• Maintain communication and provide necessary documents promptly.

Common Misconceptions Cleared:

• You don’t need a CAF number to file your own taxes.
• Your CAF number is not your personal taxpayer ID.
• The extent of access your representative has depends strictly on the authorization you grant.

FAQs:

• Do I need a CAF number for self-prepared taxes? No.
• How long to get a CAF number? IRS assigns it after form submission; it can take several weeks to process.
• Does a CAF number expire? No, but authorizations linked to it can expire or be revoked.
• If my professional already has a CAF number? They use the existing one.

For authoritative IRS details, visit IRS.gov sections on Power of Attorney and Other Authorizations, Form 2848, and Form 8821.

Learn more about Power of Attorney on our Power of Attorney glossary page and about Form 2848 on our detailed Form 2848 glossary page.