What is the SS-4 form fax number?

The SS-4 form fax number for U.S.-based applicants (all 50 states and D.C.) is 855-641-6935. This IRS Fax-TIN line is available 24 hours a day, 7 days a week.

How long does it take to get an EIN after faxing Form SS-4?

The IRS processes faxed SS-4 applications within approximately 4 business days and faxes your EIN back to the return fax number on your form. A CP 575 confirmation letter also arrives by mail within 2–3 weeks.

Do I need to put a return fax number on Form SS-4?

Yes — this is critical. If you do not include a return fax number on your SS-4, the IRS will mail your EIN instead of faxing it, adding approximately 4 weeks to the process.

Is the SS-4 fax number different for LLCs vs. corporations?

No. All domestic entity types — LLCs, corporations, partnerships, sole proprietors, trusts, and nonprofits — use the same fax number: 855-641-6935. The number only changes for international applicants.

Can I fax Form SS-4 without a physical fax machine?

Yes. Online fax services like mFax.to let you upload your completed SS-4 as a PDF and fax it to 855-641-6935 directly from your phone or computer. No fax machine or phone line required.

SS-4 Form Fax Number: Where to Fax & Step-by-Step Guide

The SS-4 form fax number for U.S.-based applicants is 855-641-6935. Fax your EIN application to the IRS and receive your Employer Identification Number in as little as 4 business days — no fax machine required.

Frequently Asked Questions

What is the SS-4 form fax number?: The SS-4 form fax number for U.S.-based applicants (all 50 states and D.C.) is 855-641-6935. This IRS Fax-TIN line is available 24 hours a day, 7 days a week.
How long does it take to get an EIN after faxing Form SS-4?: The IRS processes faxed SS-4 applications within approximately 4 business days and faxes your EIN back to the return fax number on your form. A CP 575 confirmation letter also arrives by mail within 2–3 weeks.
Do I need to put a return fax number on Form SS-4?: Yes — this is critical. If you do not include a return fax number on your SS-4, the IRS will mail your EIN instead of faxing it, adding approximately 4 weeks to the process.
Is the SS-4 fax number different for LLCs vs. corporations?: No. All domestic entity types — LLCs, corporations, partnerships, sole proprietors, trusts, and nonprofits — use the same fax number: 855-641-6935. The number only changes for international applicants.
Can I fax Form SS-4 without a physical fax machine?: Yes. Online fax services like mFax.to let you upload your completed SS-4 as a PDF and fax it to 855-641-6935 directly from your phone or computer. No fax machine or phone line required.