How to fax Form SS-4 to the IRS

Form SS-4 is the application for an Employer Identification Number (EIN). Fax is the second-fastest way to file it — and for many international applicants, the fastest available.

First: check if you can just apply online

If your principal business is in the U.S. or a U.S. territory and the responsible party has an SSN, ITIN, or existing EIN, the free online EIN assistant at irs.gov issues the number immediately — no form to send at all. Fax is the right route when you can't use the online tool: foreign applicants, responsible parties without a U.S. taxpayer ID, or entities that hit the one-EIN-per-responsible-party-per-day limit.

Form SS-4 fax numbers

Your situationFax number
Principal business, office, or legal residence in one of the 50 states or D.C. 855-641-6935
No legal residence or principal office in any state — faxing from inside the U.S. 855-215-1627
No legal residence or principal office in any state — faxing from outside the U.S. 304-707-9471
Confirm the current numbers in the Form SS-4 instructions at irs.gov/instructions/iss4 — IRS fax numbers occasionally change.

Faxing your SS-4, step by step

  1. Fill out Form SS-4 completely Incomplete forms are the main cause of delays. Double-check the responsible party's name and taxpayer ID, the entity type, and the reason for applying.
  2. Include a return fax number if you have one This matters: when you provide a fax number the IRS can reply to, it faxes your new EIN back within about four business days. Without one, the EIN comes by mail, which takes weeks.
  3. Fax the form You can send it from your computer — upload the PDF at faxer.me, enter the IRS fax number, and pay $1 for the first page plus 25¢ per page after that; no subscription. Keep the delivery confirmation.
  4. Wait for the EIN About four business days by return fax, or several weeks by mail. Don't fax a duplicate in the meantime — it can create duplicate applications.
One honest caveat: sending services like Faxer are one-way, so the IRS can't fax your EIN back to the number the fax came from. To get the four-day fax-back, list a number that can receive faxes — a subscription fax service with an inbound number, an office machine, or a colleague's line. Otherwise leave the fax-back blank and the EIN arrives by mail.

How the filing methods compare

MethodEIN arrivesWho it's for
Online assistantImmediatelyU.S. businesses with a qualifying responsible party
Fax~4 business days (with return fax)International applicants, no-SSN responsible parties
Mail~4+ weeksNo fax access, no urgency
Phone (267-941-1099)During the callInternational applicants only, business hours ET

Fax your SS-4 now

Upload the completed form, enter the IRS fax number, pay $1. No sign-up.

Go to faxer.me →

Frequently asked questions

What is the fax number for Form SS-4?

For applicants whose principal business or legal residence is in one of the 50 states or D.C., fax Form SS-4 to 855-641-6935. Applicants with no legal residence or principal office in any state fax 855-215-1627 from inside the U.S. or 304-707-9471 from outside. Verify the current numbers in the SS-4 instructions on irs.gov before sending.

How long does it take to get an EIN by fax?

About four business days, if you include a fax number the IRS can send the EIN back to. If you don't provide a return fax number, the EIN is mailed instead, which typically takes several weeks. The online EIN assistant is immediate but is only available to applicants with a U.S. principal business and a responsible party who has an SSN, ITIN, or EIN.

Can I fax Form SS-4 from my computer?

Yes. Online fax services deliver a PDF to the IRS fax lines just like a physical machine would. A pay-per-fax service costs a dollar or two for the one- or two-page form. Note that a send-only service can't receive the IRS's return fax, so give the IRS a receivable fax number or expect the EIN by mail.

What if I never receive my EIN after faxing?

Allow the full four business days for a fax-back (longer during peak season), then call the IRS Business & Specialty Tax Line at 800-829-4933 — or 267-941-1099 for international applicants. Have a copy of the SS-4 you sent and your fax delivery confirmation on hand; the IRS can look up whether the EIN was assigned rather than making you reapply.