How to fax Form SS-4 to the IRS, get your EIN in 4 days

What is Form SS-4?

Form SS-4 is the IRS application for an Employer Identification Number (EIN). The EIN is a nine-digit number assigned to businesses, estates, trusts, and other entities for tax filing and reporting purposes. You need an EIN to:

• Open a business bank account
• Hire employees and run payroll
• File business tax returns (1120, 1120-S, 1065)
• Apply for business licenses and permits
• Register a multi-member LLC, partnership, corporation, or S-corp
• Set up a trust or estate for tax purposes

Sole proprietors with no employees can use their SSN instead of an EIN, but most banks require an EIN to open a business account even for sole props.

Fax vs. online application, which to choose

The IRS offers four ways to apply for an EIN: online, fax, mail, and (for international applicants) phone. Here is when each makes sense.

Fax is the most common method for foreign owners, single-member LLCs with foreign owners, and entities applying outside the IRS online tool's hours.

What you need before faxing

Gather these items before sitting down to file:

• Form SS-4, Download the latest version from IRS.gov/pub/irs-pdf/fss4.pdf
• Legal entity name, Must match exactly what's on your state filing
• Business mailing address, Where the IRS will send physical correspondence
• Responsible party name and SSN/ITIN, The principal officer or owner; if foreign, leave SSN blank and indicate "Foreign"
• Type of entity, LLC, corporation, partnership, sole proprietor, estate, trust, etc.
• Date business started, The state filing date or date you began operations
• Reason for applying, Started new business, hired employees, banking purposes, etc.
• Return fax number (optional but recommended), A fax line where the IRS can send your EIN within 4 business days

How to fill out Form SS-4

Form SS-4 is one page with 18 numbered lines. Key sections:

• Lines 1-2: Legal name and trade name (DBA). If they are the same, leave Line 2 blank.
• Lines 4a-4b: Mailing address. Use the business address, not the registered agent address.
• Lines 5a-5b: Street address (if different from mailing). Skip if same.
• Line 6: County and state of business location.
• Line 7a: Name of responsible party.
• Line 7b: SSN/ITIN/EIN of responsible party. Foreign applicants without SSN/ITIN write "Foreign" here.
• Line 8a: Is this an LLC? If yes, complete 8b and 8c.
• Line 9a: Type of entity (check one box).
• Line 10: Reason for applying (check one box; "Started new business" is most common).
• Line 11: Date business started or acquired.
• Line 12: Closing month of accounting year (typically December for calendar year).
• Lines 13-17: Employee and revenue information. Mostly applies if you have or will have employees.
• Line 18: Has applicant ever applied for an EIN before? (Check no for new entities.)
• Third party designee section: Optional, use only if you authorize a CPA or attorney to receive the EIN on your behalf.
• Signature: Sign and date as the responsible party. Print name and title.

Cover sheet template for SS-4

The IRS does not require a specific cover sheet, but a clean cover speeds processing and reduces errors. Use this template:

Faxend customers do not need to manually create a cover sheet, the app generates this automatically when you select IRS as the recipient.

Step-by-step: faxing Form SS-4

What happens after you fax

Within 4 business days, the IRS Cincinnati EIN Operation processes your Form SS-4. If everything is complete and matches IRS records:

• The IRS faxes your assigned EIN to the return fax number you listed (4 business days)
• If no return fax number, the IRS mails the EIN by certified letter (4-5 weeks)

The EIN is permanent, it never expires and never needs to be renewed. Save it. Use it on every business tax filing, bank application, and government form.

Common mistakes to avoid

Filing duplicate applications. Each entity gets only one EIN. If you fax SS-4 and don't hear back in 4 business days, do not fax again, call the IRS Business Line (1-800-829-4933) to check status. Filing duplicates creates duplicate EINs and accounting headaches.

Using the wrong fax number. 855-641-6935 is for US filers only. International filers must use 855-215-1627. Sending to the wrong number routes your application to the wrong service center and delays processing.

Putting SSN where EIN goes. If you already have an EIN for a different entity, do not put it in Line 7b (responsible party), that line wants the responsible party's personal SSN/ITIN.

Listing a registered agent address. Use your actual business mailing address on Lines 4a-4b. The IRS sends correspondence here. A registered agent address means your CPA or attorney sees IRS letters before you do.

Forgetting to sign. Unsigned SS-4 is rejected. The signer must be the responsible party listed on Line 7a, not a CPA, attorney, or staff member, unless properly authorized via Form 2848.

Sources

This guide is based on the following IRS sources:

• About Form SS-4, IRS.gov
• Form SS-4 PDF, IRS.gov
• How to apply for an EIN, IRS.gov
• IRS Publication 1635, Understanding Your EIN

Frequently asked questions