FAX: Third-party authorization for CAF processing
To: Internal Revenue Service, CAF Unit, [Memphis / Ogden / Philadelphia International CAF]
Fax: [855-214-7519 / 855-214-7522 / 855-772-3156 / 304-707-9785]
From: [Representative or designee name], [Firm]
CAF number: [CAF number, or 'None, new representative']
Phone: [Phone] Fax: [Return fax]
Date sent: [Date] Total pages including cover: [Number]
Enclosed:
- [Form 2848 / Form 8821] for [Taxpayer name], TIN ending [last four digits], [number of pages] pages
- [Attachment, e.g. continuation list of representatives or designees, if any]
Checked before sending:
- Line 4 (specific use not recorded on CAF) is not checked. [If it is checked, do not send to CAF; send to the IRS office handling the matter.]
- Taxpayer and representative signatures are handwritten (no typed, digital or electronic signatures).
- One taxpayer per form. Joint filers each have their own form.
- Tax matters, form numbers and specific years or periods are entered on line 3.
- Representative designation and licensing jurisdiction and number are completed (Form 2848, Part II).
- This authorization has not been submitted online or by mail.
Confidentiality notice: This transmission contains federal tax information intended only for the IRS CAF unit. If received in error, notify the sender at [Phone] and destroy all copies.
When to fax instead of upload
The instructions for both forms list three ways to submit when line 4 is not checked: online at IRS.gov/Submit2848, by fax, or by mail. For individual authorizations the IRS also points practitioners to Tax Pro Account, where “Most requests record immediately to the Centralized Authorization File (CAF).” Faxing is still common when the client signs in ink at the office, when the authorization is for a business, or when you want a fax confirmation as proof of receipt.
Electronic signatures change the answer. The Form 2848 instructions say “Forms 2848 with an electronic signature image or digitized image of a handwritten signature may only be submitted to the IRS online at IRS.gov/Submit2848.” If the client signed through an e-signature platform, do not fax it. For the choice between the two forms, see Form 2848 vs. 8821.
Where to fax it
The Where To File Chart in both sets of instructions assigns the CAF unit by where the taxpayer lives. IRM 21.3.7 (rev. Sept. 15, 2026) lists the same numbers for its staff.
| Taxpayer location | CAF unit | Fax |
|---|---|---|
| AL, AR, CT, DE, DC, FL, GA, IL, IN, KY, LA, ME, MD, MA, MI, MS, NH, NJ, NY, NC, OH, PA, RI, SC, TN, VT, VA, WV | Memphis, 5333 Getwell Road, Stop 8423, Memphis, TN 38118 | 855-214-7519 |
| AK, AZ, CA, CO, HI, ID, IA, KS, MN, MO, MT, NE, NV, NM, ND, OK, OR, SD, TX, UT, WA, WI, WY | Ogden, 1973 Rulon White Blvd., MS 6737, Ogden, UT 84201 | 855-214-7522 |
| APO/FPO, American Samoa, CNMI, Guam, USVI, Puerto Rico, foreign country | International CAF Team, 2970 Market Street, MS 4-H14.123, Philadelphia, PA 19104 | 855-772-3156; 304-707-9785 from outside the U.S. |
Both instruction sets add: “These numbers may change without notice.” Check the Recent Developments section on the form’s IRS page before relying on a saved number. The CAF function that receives the form processes it regardless of state mapping, except that international forms received in Memphis or Ogden are forwarded to Philadelphia.
Why each checklist item is there
| Checklist item | Source |
|---|---|
| Line 4 not checked | “If you check the box on line 4, mail or fax Form 2848 to the IRS office handling the specific matter.” A specific-use form is not recorded on the CAF. |
| Handwritten signatures | “You must handwrite your signature on Form 2848 if you file it by mail or by fax.” The Form 8821 instructions say the same. |
| One taxpayer per form | Joint filers: “your spouse must execute his or her own power of attorney on a separate Form 2848”. The online page also says to “Submit one form at a time, even for married filing jointly taxpayers.” |
| Not also submitted online | The online submission page: “If you already faxed or mailed a form, don’t submit it online.” |
| Specific periods on line 3 | See why the CAF unit rejects a 2848 for the line 3 rules. |
What CAF does with it
Faxes to CAF are routed into an electronic system the IRM calls EFS, and the IRM says “Receipts received in the CAF Functions are processed first in first out (FIFO), regardless of the method used to submit the authorization.” The IRM removed a stated five-business-day processing time in 2026 and now points to the Processing Status for Tax Forms page on IRS.gov. For proof of submission, the IRM notes that “When fax receipts are dated and time stamped via the fax machine, no further action is required as evidence of receipt.” Keep your fax confirmation with the signed original.
When two authorizations cover the same matters and years, IRM 21.3.7 treats the one with the most recent taxpayer signature date as controlling. Once the form posts you will receive a CAF number if you did not have one, and can use Practitioner Priority Service and transcript access for the listed periods.
Mistakes that cause rejections
- Faxing a form with a typed or e-signature.
- Sending the same form online and by fax, which creates duplicates.
- Combining spouses on one form.
- Faxing a line 4 specific-use form to CAF, where it will not be recorded.
- Using an outdated fax number from an old cover sheet.
Questions practitioners ask
Does the IRS require a cover sheet?
The instructions do not require one. A cover sheet that lists the contents and page count helps the CAF clerk split a multi-form fax correctly; IRM 21.3.7 describes staff splitting faxes that contain several authorizations.
Can I fax several clients' forms in one transmission?
The IRM describes CAF staff processing and splitting faxes with multiple authorizations, so it is possible. A separate transmission per taxpayer makes it easier to match the fax confirmation to each client.
Should the cover sheet show the full SSN?
The IRS does not prescribe cover sheet content. Many firms show only the last four digits on the cover because the full TIN is on the form itself.
How do I revoke an authorization by fax?
Write REVOKE across the top of the first page of a copy of the authorization with a current signature and date, and fax it to the same CAF unit. See revoking and withdrawing authorizations.
What if the client signed electronically?
Submit online at IRS.gov/Submit2848. The online page requires you to authenticate the taxpayer’s identity when you have no prior relationship and the taxpayer signs electronically in a remote transaction.