How to complete and submit Form SS-4 as a foreign company

Form SS-4 is the IRS application for an Employer Identification Number (EIN). Foreign companies applying without a U.S. entity must complete it by fax or mail, or by phone. This article explains how to fill in the fields that are non-obvious for non-U.S. applicants and how to submit it correctly.

Before you start

Have the following ready:

The legal name of your company exactly as it appears in your home country registration documents
The name, title, and personal tax ID of the responsible party (see Line 7 below)
Your U.S. mailing address (from your virtual mailbox service)
The date your company started doing business

Download Form SS-4 from the IRS website. Print it or complete it in a PDF editor before submitting.

How to complete the key fields

Lines 1 and 2: Company name

Line 1: Enter the full legal name of your company.
Line 2: Enter a trade name only if your company does business under a name different from line 1. Leave it blank otherwise.

Lines 4 and 5: Address

Line 4a/4b: Enter your U.S. mailing address (the virtual mailbox address). This is where the IRS will send your EIN confirmation letter.
Lines 5a/5b: Leave blank if the same as line 4.

Line 6: County and state

If your company has no U.S. physical presence (no office, warehouse, or fulfillment center), leave this blank.

If you do have a physical location in the U.S. (for example, a warehouse or a third-party logistics center storing your inventory), enter the county and state where that location is. Note that physical presence in a state creates physical nexus there, which triggers sales tax obligations in that state regardless of your sales volume.

Line 7: Responsible party

The responsible party is the individual who controls the company. For most small foreign companies, this is the owner or a director.

Line 7a: Enter that person's full name.
Line 7b: Enter their U.S. Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN) if they have one.

If the responsible party has no U.S. tax ID, write their home-country tax identification number in line 7b and note the country next to it (e.g., "ES12345678A - Spain"). The IRS accepts this for foreign applicants; it may slow processing slightly.

Alternatively, you can apply by phone (see the submission section below), which bypasses line 7b entirely.

Lines 8a, 8b, and 8c: LLC question

If your company is a limited liability company or its equivalent in your home country (for example, a Spanish SL, a French SARL, a German GmbH, a Portuguese Lda, or a Dutch BV), check "Yes" on line 8a and enter the number of members (socios, associés, Gesellschafter, etc.) on line 8b. On line 8c, check "No" since the entity was not organized in the United States.

If your company is a corporation, a sole proprietorship, or any other structure, check "No" on line 8a and leave 8b and 8c blank.

Line 9a: Type of entity

Check the box that matches your company structure. For most foreign companies, this will be "Corporation" or "Other" (with a description such as "Foreign private limited company").

If you check "Corporation," the form asks for the tax return form number to be filed. Enter 1120-F (U.S. Income Tax Return of a Foreign Corporation). Note that whether your company is actually required to file Form 1120-F depends on whether you have U.S.-source income or a U.S. trade or business, which is a separate question from sales tax registration. For the SS-4, entering "1120-F" is the standard answer for foreign corporations.

Line 10: Reason for applying

Check "Other" and write "Required to register for U.S. state sales tax" in the space provided.

Line 11: Date business started

Enter the date your company first started selling to U.S. customers. Do not enter your company's incorporation date in your home country. The IRS is asking about the start of U.S. business activity, which is what the EIN is being obtained for.

Line 12: Closing month of accounting year

Enter the last month of your fiscal year (for example, "December").

Lines 13 to 15: Employees

If you have no U.S.-based employees, enter "0" on line 13 and leave lines 14 and 15 blank.

Lines 16 and 17: Business activity

Line 16 has fixed checkboxes (Construction, Retail, Finance, Manufacturing, etc.). There is no Software or Online Services option. If you sell software, SaaS, or digital products, check "Other" and enter "Software / Online services" on line 17.

Line 18: Previous EIN

Check "No" unless your company has applied for a U.S. EIN before.

How to submit

Foreign applicants cannot use the IRS online EIN application. You have three options:

Option A: Phone (fastest)

Call the IRS EIN International Operation at +1-267-941-1099, Monday to Friday, 6 a.m. to 11 p.m. Eastern Time. Have your completed SS-4 in front of you. The agent will ask for the information on the form and issue the EIN by the end of the call.

This is the recommended option if the responsible party does not have a U.S. tax ID, since it avoids any ambiguity around line 7b.

Option B: Fax (4 business days)

Fax your completed SS-4 to the IRS EIN International Operation. The current fax number is listed in the IRS SS-4 instructions under "Where to File or Fax." Verify the number there before sending, as IRS fax numbers change periodically.

Include a cover sheet with your company name and a return fax number. The IRS will fax your EIN confirmation back within 4 business days.

Option C: Mail (4 to 6 weeks)

Mail your completed SS-4 to:

Internal Revenue Service

Attn: EIN International Operation

Cincinnati, OH 45999

United States

Processing by mail takes 4 to 6 weeks. Use a tracked international mail service and keep your tracking number.

What happens next

The IRS will issue your EIN in a letter (CP 575). Keep this letter: some states require it as proof of your EIN during the sales tax registration process.

Once you have your EIN, you are ready to register for sales tax in the states where you have economic nexus. See Requirements for filing taxes in the US if you are not a resident company for the full overview.