What Form SS-4 is for
Form SS-4 is how you apply for an Employer Identification Number. An EIN is a 9-digit number, like 12-3456789, assigned to sole proprietors, corporations, partnerships, estates, trusts, and other entities for tax filing and reporting. What you put on the form sets up your business tax account. The EIN covers your business activities only, and it does not replace your SSN or ITIN.
File it if your entity does not have an EIN yet but has to show one on a return, statement, or other document. Employers, corporations, partnerships, trusts, estates, churches, government agencies, Indian tribal entities, certain individuals, and others use it. Page 2 of the form matches common situations to the lines you need to fill in.
Who needs to file Form SS-4?
File Form SS-4 if your entity does not already have an EIN but is required to show one on any return, statement, or other document. The form is for employers, corporations, partnerships, trusts, estates, churches, government agencies, Indian tribal entities, certain individuals, and others. A partnership, corporation, REMIC, nonprofit organization, or farmers' cooperative must use an EIN for any tax-related purpose even without employees.
- You started a new business that needs an EIN
- You hired or will hire employees, including household employees
- You opened a bank account and need an EIN for banking purposes only
- You changed your type of organization, such as incorporating a sole proprietorship
- You purchased a going business and do not already have an EIN
- You created a trust that is not a grantor trust or an IRA trust
- You are administering an estate and need an EIN to report estate income on Form 1041
- You are a foreign person who needs an EIN to comply with IRS withholding regulations
How do you apply for an EIN?
The IRS recommends applying electronically if you can. You can apply online only if you have a legal residence, principal place of business, or principal office or agency in the United States or U.S. territories. Online, you receive the EIN and can use it right away to file a return or make a payment. The principal officer, general partner, grantor, owner, or trustor must have a valid SSN, EIN, or ITIN to use the online application.
If you have none of those in the United States or U.S. territories, you cannot apply online. You may call 267-941-1099, which is not a toll-free number, from 6:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. The IRS no longer issues EINs by telephone for domestic taxpayers. Use only one method for each entity so you do not end up with more than one EIN.
- By fax, you generally receive your EIN within 4 business days
- By mail, complete the form at least 4 to 5 weeks before you need the EIN, and it arrives in about 4 weeks
- EIN issuances are limited to one per responsible party, per day, by any method
- Call 800-829-4933 to verify a number or ask about the status of an application by mail
Where do you send Form SS-4?
Where you fax or mail it depends on where you are based. If you have a legal residence, principal place of business, or principal office or agency in one of the 50 states or the District of Columbia, fax the form to 855-641-6935 or mail it to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999.
If you have none of those in any state or the District of Columbia, which can happen in a U.S. territory or an international location, fax the form to 855-215-1627 from inside the United States or 304-707-9471 from outside it. Mail goes to Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999. Fax-TIN is available 24 hours a day, 7 days a week and can only be used to apply for an EIN. Put your fax number on the form so the IRS can fax the EIN back.
How do you fill out Form SS-4?
Type or print clearly and keep a copy for your records. The chart on page 2 of the form tells you which lines to complete for your situation, so you may not need all of them. Generally, enter N/A on lines that do not apply. Line 9a and line 10 are different, because you must check one box on each and the instructions say not to enter N/A there. Line 1, line 7b, line 16, and line 17 also require an entry.
Sign and date the application. The individual signs if the applicant is an individual. The president, vice president, or other principal officer signs for a corporation. A responsible and duly authorized member or officer with knowledge of its affairs signs for a partnership, government entity, or other unincorporated organization. The fiduciary signs for a trust or estate. Foreign applicants may have any duly authorized person sign. Fill in the Third Party Designee section only if you want that person to receive the EIN and answer questions about the form.
- Line 14 applies if you expect employment tax liability of $1,000 or less in a full calendar year
- That generally means total wages of $5,000 or less, or $6,536 or less if you are in a U.S. territory
- Once you check the line 14 box, you must keep filing Form 944 until the IRS instructs you to file Form 941
- Line 18 asks whether this entity ever received an EIN before, and you write the previous EIN if it did
What changed in the December 2025 revision?
The instructions list one item under What's New. The fax numbers and mailing addresses moved, so you now find them under Apply by fax and Apply by mail. The instructions also recommend applying for your EIN electronically when that is possible for you. The form itself is fillable, and once completed, it is suitable for faxing or mailing to the IRS. There is also a Spanish-language version, Form SS-4 (sp).
What if a return is due before your EIN arrives?
If you do not have an EIN by the time a return is due, write "Applied For" and the date you applied in the space shown for the number. Do not show your SSN as an EIN on returns. If a tax deposit is due first, send your payment to the Internal Revenue Service Center for your filing area as shown in the instructions for the form you are filing. Make the check or money order payable to the "United States Treasury" and show your name as it appears on Form SS-4, your address, the type of tax, the period covered, and the date you applied.
- Use Form 8822-B to report changes to your responsible party, address, or location
- Report a change in responsible party to the IRS within 60 days
- A sole proprietor generally files only one Form SS-4 and needs only one EIN
- A new EIN is required if a sole proprietorship incorporates or enters into a partnership
- Each corporation in an affiliated group must have its own EIN
Form SS-4 line by line
| Line | What goes there |
|---|---|
| 1 | The legal name of the entity or individual getting the EIN, exactly as on the social security card, charter, or other legal document. An entry is required. |
| 2 | The trade name, or doing business as name, if it differs from line 1. Sole proprietors put their own name on line 1 and the business name here. |
| 4a-4b | Your mailing address for correspondence. A foreign address needs the city, province or state, postal code, and the full country name spelled out. |
| 5a-5b | The entity's physical address, only if it differs from the mailing address. Do not enter a P.O. box here. |
| 7a-7b | The name of the responsible party plus their SSN, ITIN, or EIN. That is the person who ultimately owns or controls the entity. |
| 8a-8c | Whether this is for an LLC or foreign equivalent, how many members it has, and whether it was organized in the United States. |
| 9a | The type of entity, one box only. This is not an election of your tax classification. |
| 10 | Your single reason for applying, such as started new business, hired employees, banking purpose, or created a trust. A selection is required. |
| 11 | The date the business started or was acquired. Estates enter the date of death or the date the estate was legally funded. |
| 12 | The last month of your accounting or tax year. A calendar year is 12 consecutive months ending on December 31. |
| 13 | The highest number of agricultural, household, and other employees you expect in the next 12 months. Enter -0- if none. |
| 14 | Check this to file Form 944 once a year instead of Form 941 quarterly, if you qualify. Leave it blank and you must file Form 941 every quarter. |
| 16 | One box for the principal activity of your business. Check Other and describe it if none of the listed boxes fits. You must check a box. |
| 17 | More detail on your principal line of merchandise sold, construction work done, products produced, or services provided. An entry is required. |
Source: IRS, Form SS-4 (Rev. Dec 2025) and Instructions for Form SS-4, Application for Employer Identification Number (EIN). This page explains the form in plain English. It is not tax advice.