Where to Fax IRS Form SS-4 (EIN Application)

Where to Fax Form SS-4

The IRS splits fax destinations based on your entity’s location. If your business has a legal residence, principal place of business, or principal office in one of the 50 states or the District of Columbia, fax Form SS-4 to 855-641-6935. If your entity doesn’t meet that criteria—for example, you’re in a U.S. territory or operating internationally—fax to 855-215-1627 from within the U.S., or 304-707-9471 from outside the U.S.

Entity Location	Fax Number	Hours	Processing Time
50 states or D.C.	855-641-6935	24/7	Generally 4 business days
U.S. territories/international (from within U.S.)	855-215-1627	24/7	Generally 4 business days
International (from outside U.S.)	304-707-9471	24/7	Generally 4 business days

After faxing, the IRS will fax your EIN back to the number you provide on Form SS-4—so make sure you include your fax number on the form. You should receive your EIN within 4 business days if everything is filled out correctly.

a decision-tree infographic showing which IRS fax number to use for Form SS-4 based on entity location — IRS Form SS-4 Fax Number Guide

Before You Fax: Required Information Checklist

Incomplete forms cause delays. Before you send your fax, make sure every required field is filled out:

Legal name of entity — Exactly as it appears on your organizing document or Social Security card
Trade name (if applicable) — Your “doing business as” name, if different from legal name
Responsible party information — Name and taxpayer ID number of the person who controls the entity (not a nominee)
Entity type — Corporation, LLC, partnership, etc.
Reason for applying — Started new business, banking purpose, changed type of organization, etc.
Business address — Mailing address, street address, county, and state
Date business started or acquired — Required for most entity types
Highest number of employees expected — In the next 12 months

The IRS instructs applicants to enter “N/A” on lines that don’t apply—this speeds up processing and reduces follow-up requests.

Make sure the signature and date fields are completed. If you’re using a third-party designee, that section must also be signed for the authorization to be valid.

a step-by-step checklist infographic for preparing IRS Form SS-4 before faxing — Preparing IRS Form SS-4 Checklist

How to Confirm Your Fax Was Received

The IRS doesn’t send fax transmission confirmations. Instead, they’ll fax your EIN directly to the fax number you provided on Form SS-4.

If you don’t receive your EIN within the expected timeframe, here’s what to do:

Wait at least 4 business days before following up—that’s the standard processing window for faxed applications.
Call the IRS Business & Specialty Tax Line at 800-829-4933 to check your application status.
Have your Form SS-4 information ready when you call—the IRS uses that information to locate your application and verify your account details.

Alternative Methods to Fax (Faster Options)

Faxing isn’t the fastest way to get an EIN. Here are your other options:

Online application — Immediate EIN if approved. Available only for entities with a principal business, office, or legal residence in the U.S. or U.S. territories. Apply at IRS.gov/EIN.
Phone application — Same-day EIN for international applicants only. Call 267-941-1099, Monday–Friday, 6:00 a.m.–11:00 p.m. Eastern Time. (The IRS no longer issues EINs by phone for domestic taxpayers.)
Mail application — Approximately 4 weeks. The IRS recommends applying at least 4 to 5 weeks before you need your EIN.

If you’re eligible, use the online application—it’s the fastest option and gives you an EIN immediately.

a comparison infographic of four EIN application methods and their timing — EIN Application Methods Comparison

Common Fax Submission Mistakes to Avoid

Here’s what slows down processing or triggers rejections:

Faxing to the wrong number based on entity location — Domestic entities use 855-641-6935; international/territory entities use a different number. Double-check before sending.
Missing signature or date — The form won’t be processed without a signature and date in the applicant section.
No return fax number — If you don’t include your fax number on Form SS-4, the IRS can’t fax your EIN back to you.
Illegible fax transmission — If the IRS can’t read your form, they’ll have to follow up or reject it outright.
Incomplete responsible party information — The IRS needs the responsible party’s name and taxpayer ID. Leaving this blank causes delays.
Using an outdated form revision — Always verify you’re using the current version of Form SS-4 before faxing.

an infographic highlighting six common Form SS-4 fax submission mistakes that cause delays or rejection — Form SS-4 Fax Mistakes

What to Do If You Don’t Receive Your EIN

The normal processing timeline for faxed SS-4 forms is 4 business days.

If you haven’t received your EIN after that window:

Verify the processing timeline has elapsed — Don’t call before 4 business days have passed.
Call the IRS Business & Specialty Tax Line at 800-829-4933 — This is the number for EIN assignment and application status inquiries.
Have your completed Form SS-4 details ready — The IRS uses the information from your application to locate your account and assign your EIN over the phone if needed.

Don’t submit a duplicate application while waiting—it just creates confusion and further delays.

Create a step-by-step follow-up workflow infographic for applicants who have not received an EIN after faxing Form SS-4 — How to Follow Up on EIN Delays

Need to send a fax but don’t have a fax machine? ThirtyFax lets you send your Form SS-4 online—no account, no subscription, just pay once and send. You can fax up to 5 pages free or up to 20 pages for a flat €4.99.

Written by

Bernard Bado

I created ThirtyFax after needing to send a single fax and refusing to pay for a monthly subscription to do it. I write here about faxing, document workflows, and the surprisingly stubborn role fax still plays in modern business.

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