The CAF number on Form 2848 is a unique nine-digit identifier the IRS assigns to a representative the first time they file a third-party authorization. If you already have one, it appears on the CP547 notice the IRS mailed when it was issued and on every Form 2848 you’ve filed since. If you’ve never filed an authorization before, you don’t apply separately: write “None” in the CAF number field, and the IRS will assign one automatically when it processes the form.
What the CAF Number Is
The Centralized Authorization File is the IRS database that tracks every active third-party authorization. Your CAF number is your personal identifier inside that system, linking you to each client who has authorized you to act on their behalf or receive their confidential tax information.1Internal Revenue Service. What Is a CAF Number
It is not your Social Security Number, Employer Identification Number, or Preparer Tax Identification Number.1Internal Revenue Service. What Is a CAF Number A PTIN identifies someone who prepares returns for compensation; a CAF number identifies someone authorized to represent a taxpayer or receive their tax information. Many practitioners hold both. You enter your PTIN on returns you prepare, and your CAF number on authorization forms like Form 2848.
The number itself does not grant authority to practice before the IRS. It simply tells the IRS’s systems who is authorized for which taxpayer, which tax matters, and which periods. A CAF number can be assigned to an individual representative or to a business entity.1Internal Revenue Service. What Is a CAF Number
How To Find a CAF Number You Already Have
Three places, in order of how quickly they’ll get you the answer.
The CP547 notice. When the IRS first assigned your CAF number, it mailed you a CP547 notice confirming the assignment and identifying the taxpayer account it was linked to.2Internal Revenue Service. Understanding Your CP547 Notice That notice is the most reliable record. Check your correspondence file first.
A prior Form 2848. Your CAF number appears in the representative information section of every authorization you’ve filed since receiving it. Any one of those forms will show it.
The Practitioner Priority Service. Call 866-860-4259. Assistors are available weekdays from 7 a.m. to 7 p.m. local time; Alaska and Hawaii follow Pacific time, and Puerto Rico runs 8 a.m. to 8 p.m. local time.3Internal Revenue Service. Practitioner Priority Service After the assistor verifies your identity, they can give you the number over the phone. If they can’t verify you, the IRS mails a letter to the address on file instead.2Internal Revenue Service. Understanding Your CP547 Notice
How First-Time Representatives Get One
There is no separate application. The IRS assigns a CAF number automatically the first time you successfully file a Form 2848 or Form 8821.4Internal Revenue Service. The Centralized Authorization File (CAF) – Authorization Rules
In the CAF number field on the form, first-time filers enter “None.” The IRS then issues the number directly to the representative.5Internal Revenue Service. Instructions for Form 2848 – Power of Attorney and Declaration of Representative After the form is processed, the IRS mails a CP547 notice to you with the newly assigned number.2Internal Revenue Service. Understanding Your CP547 Notice
From that point forward, use that same CAF number on every future authorization. Leaving it off slows processing and can cause the IRS to treat you as a first-time filer all over again.
Where the CAF Number Goes on Form 2848
The CAF number lives in Part II, the representative information section. Along with the number, each representative enters their name, address, telephone number, and professional designation. The designations recognized on Form 2848 include attorneys, CPAs, enrolled agents, enrolled actuaries, officers of an entity, full-time employees, family members, unenrolled return preparers, enrolled retirement plan agents, and qualifying students or law graduates.5Internal Revenue Service. Instructions for Form 2848 – Power of Attorney and Declaration of Representative
Each designation has its own identifying detail attached. Attorneys enter their state abbreviation and bar number. CPAs enter their state and license number. Enrolled agents enter their enrollment card number. The CAF number is separate from all of these and required regardless of designation.
Form 8821 Also Triggers a CAF Number
Worth knowing if you’re deciding which form to file: both Form 2848 and Form 8821 result in a CAF number assignment, but they grant different authority. Form 2848 authorizes a representative to act on the taxpayer’s behalf before the IRS, including responding to notices, attending meetings, and negotiating settlements. Form 8821 only authorizes someone to inspect or receive the taxpayer’s confidential tax information; it carries no authority to represent.6Internal Revenue Service. About Form 2848, Power of Attorney and Declaration of Representative
If you just need to pull transcripts for a client, Form 8821 is enough. If you need to speak for them, you need Form 2848. Either way, the first one you file gets you into the CAF system, and the number you receive is the one you’ll use on every authorization after.