Fill SS-4 – Application for Employer Identification Number (EIN)

Who this page is for

This page helps business owners, nonprofit organizers, trustees, estate executors, and other responsible parties fill the official IRS Form SS-4 online and download a completed PDF to request an Employer Identification Number. It is intended for people who need an EIN for federal tax administration but prefer a simple, browser-based way to complete the form without creating an account or sending their information to a third-party server.

What is Form SS-4?

Form SS-4, Application for Employer Identification Number (EIN), is the application the Internal Revenue Service uses to assign an Employer Identification Number. The EIN functions as a federal tax ID for businesses and certain other entities, similar to how a Social Security Number identifies an individual for tax purposes. The form collects details about the entity’s legal name, address, responsible party, type of organization, reason for applying, and principal activity.

Used to apply for an Employer Identification Number (EIN) for a business or other entity so it can file and report federal taxes.

On this page you fill the official IRS Form SS-4 (Rev. December 2023) in a browser-friendly way and then download the completed PDF. You can then follow the IRS instructions to fax, mail, or otherwise submit the application using the methods the IRS currently supports.

Example situations where someone may use Form SS-4

The IRS requires an Employer Identification Number in many common business and administrative situations. Examples include:

• Starting a corporation, partnership, or multi-member LLC that will file separate tax returns.
• Hiring employees and needing an EIN for payroll tax reporting and IRS Forms 941 or 944.
• Creating a trust, estate, or nonprofit organization that requires its own federal tax ID number.
• Opening certain business bank accounts that require an EIN instead of using an individual's Social Security Number.
• Acting as a plan administrator for a retirement plan or similar arrangement that needs its own EIN for reporting.

These examples are illustrative and based on general IRS guidance. They do not replace the official instructions for Form SS-4 or advice from a tax professional.

How to fill Form SS-4

The on-page helper text next to each field walks you through the details. The summary below shows how the main lines of Form SS-4 map to the questions above, so you can quickly review each section before you download your filled SS-4 PDF. This structure can also help you follow along with the official IRS instructions while you complete the form.

Lines 1–7: Basic entity information

These lines identify who is applying for the EIN, where the entity is located, and who is responsible for it.

• 1. Legal name of entity (or individual) for whom the EIN is being requested

  Enter the exact legal name that will appear on federal tax returns. For a sole proprietor, this is usually the individual's name from their personal tax return. For a corporation, partnership, or LLC, use the legal name in the formation documents.

• 2. Trade name of business (if different from line 1)

  If the entity uses a "doing business as" (DBA) or trade name that is different from the legal name on line 1, enter it here. If you do not use a separate trade name, you can leave this line blank.

• 3. Executor, administrator, trustee, or “care of” name

  Use this line for estates, trusts, or situations where someone is acting on behalf of the entity. For regular operating businesses, this line is often left blank unless another party receives IRS mail for the entity.

• 4a–4b. Mailing address (number, street, room/apartment/suite, city, state, ZIP)

  Enter the mailing address where you want IRS correspondence about this EIN to be sent. Include the number, street, and any apartment or suite information, plus city, state, and ZIP code. This is often the primary business or administrative address.

• 5a–5b. Street address (if different) (Do not enter a P.O. box.)

  If the physical location of the business is different from the mailing address on line 4, enter the street address here. Do not use a P.O. box on this line; it is meant for the actual place where the business operates or records are kept.

• 6. County and state where principal business is located

  Enter the county and state where the principal business is located. This helps the IRS classify the entity's location for administrative purposes.

• 7a–7b. Name of responsible party and SSN, ITIN, or EIN

  List the individual who ultimately owns or controls the entity or exercises ultimate effective control. On line 7b, enter that person's SSN, ITIN, or EIN as instructed. The IRS uses this information to identify a human contact for the entity.

Lines 8–9: LLC information and type of entity

These lines tell the IRS whether the applicant is an LLC and how it will be treated for federal tax purposes.

• 8a. LLC status

  Check "Yes" if the entity is a limited liability company, then complete lines 8b and 8c. Check "No" if the entity is not an LLC (for example, a corporation formed directly under state law or a partnership that is not organized as an LLC).

• 8b. Number of LLC members

  Enter the total number of members in the LLC. The number of members helps determine whether the LLC is treated as a disregarded entity, partnership, or corporation for federal tax purposes.

• 8c. Was the LLC organized in the United States?

  Indicate whether the LLC was formed under the laws of a U.S. state or territory. This helps the IRS distinguish domestic entities from foreign entities that may have different filing requirements.

• 9a. Type of entity (check only one box)

  Choose the box that best describes how the entity is organized for federal tax purposes, such as sole proprietor, corporation, partnership, nonprofit organization, government entity, or other specialized category. If you select "Other," use the space provided to briefly describe the entity type.

• 9b. State or foreign country where incorporated or organized (if applicable)

  If the entity is a corporation or similar organization, enter the state or foreign country where it was legally formed. This may differ from the state where it currently operates.

Lines 10–15: Reason for applying, dates, and employees

These lines explain why you are applying for an EIN and provide basic timing and employee information.

• 10. Reason for applying (check only one box)

  Select the main reason you are requesting an EIN, such as starting a new business, hiring employees, banking purposes, purchasing an existing business, creating a trust or pension plan, or complying with IRS withholding regulations. If you select an option that asks for more detail, briefly describe the type of business or change.

• 11. Date business started or acquired

  Enter the month, day, and year when the business began operations or when you acquired it. For trusts or estates, use the date the trust was funded or the date of death, as described in the IRS instructions.

• 12. Closing month of accounting year

  Enter the last month of the entity's tax year, which is often December for calendar-year filers. Some entities use a different fiscal year; if so, enter the month that ends the fiscal year.

• 13. Highest number of employees expected in the next 12 months

  Estimate the highest number of Agricultural, Household, and Other employees you expect to have in the next 12 months. If no employees are expected, enter "0" for each category and follow the IRS instructions about employment tax returns.

• 14. Employment tax liability and Form 944 / Form 941 preference

  If you expect your total employment tax liability to be $1,000 or less for the year and you want to file Form 944 annually instead of Form 941 quarterly, you can check the box as described in the SS-4 instructions. If you do not check this box, the IRS generally expects quarterly filings when you have employees.

• 15. First date wages or annuities were paid, or will be paid

  Enter the month, day, and year when you first paid (or expect to pay) wages or annuities that are subject to federal employment tax. If you have not yet paid anyone, use the date you expect to pay your first employee.

Lines 16–18: Principal activity, line of business, and prior EIN

These lines describe what the entity does and whether it has had an EIN before.

• 16. Principal activity of your business

  Check the box that best describes the main type of activity, such as construction, manufacturing, retail, health care, finance, or another category listed on the form. If you choose "Other," briefly describe the principal activity in the space provided.

• 17. Indicate principal line of merchandise sold, services provided, or work performed

  Describe, in a short phrase, what the entity primarily does or sells. Examples include "online retail clothing," "residential plumbing," or "software consulting." The goal is to give the IRS a clear, plain-language description of your main business line.

• 18. Has the applicant entity ever applied for and received an EIN?

  Indicate whether the entity (or a substantially similar predecessor) has previously received an EIN. If you answer "Yes," enter the prior EIN if known. The IRS uses this information to avoid issuing duplicate numbers and to link related accounts.

Third Party Designee and signature section

• Third Party Designee section

  Complete this section only if you want to authorize someone else, such as a tax professional or payroll provider, to communicate with the IRS about this EIN application. Enter the designee's name, telephone number, address, and fax number if applicable.

• Signature, name and title, and applicant contact information

  After reviewing all entries, have an authorized individual sign and date the form. Enter the signer's name and title, along with the applicant's telephone and fax numbers. On this site, the signature area is left blank so you can sign by hand or use an electronic signature method that the IRS accepts for the way you submit the form.

After reviewing your entries, download the filled PDF, add any required signatures, and submit it to the IRS using an accepted method, such as the procedures described in the official EIN application instructions.

Common mistakes on Form SS-4

• Leaving line 1 blank or entering a trade name instead of the legal name that will appear on the entity's tax returns.
• Choosing an entity type in line 9 that does not match how the organization is actually structured or taxed under IRS rules.
• Forgetting to indicate whether an LLC is domestic or foreign, or omitting the number of LLC members on line 8b.
• Using an address that is not suitable for receiving IRS mail, such as a temporary address that will soon change, without updating it later.
• Providing an incorrect or missing SSN, ITIN, or EIN for the responsible party, which can slow down processing.
• Checking a reason for applying on line 10 that does not match what is happening in practice, such as "started a new business" when the form is really for a change in ownership.
• Leaving line 11 blank or entering an unrealistic business start date that does not match other records.
• Forgetting to sign and date the form or to complete the Third Party Designee section correctly when someone else will contact the IRS about the application.

When Form SS-4 is usually not used

Form SS-4 is widely used, but there are situations where an EIN application is not needed or where other processes apply instead:

• Individuals who only file Form 1040 and do not operate a separate business entity typically do not need an EIN and use their Social Security Number instead.
• Some disregarded single-member LLCs use the owner's existing EIN or SSN rather than applying for a separate EIN, depending on the situation described in IRS guidance.
• Entities that already have an EIN and are not undergoing a change that requires a new number normally continue using the existing EIN.
• Certain government agencies and large organizations may handle EINs through internal procedures instead of an individual SS-4 filing.

These are broad IRS distinctions. This information is not legal or tax advice, and the IRS instructions explain when an EIN is or is not required for specific situations.

Where to find the official IRS instructions for Form SS-4

The Internal Revenue Service publishes the official instructions for Form SS-4 on IRS.gov along with the latest revision of the form. Those instructions explain who needs an EIN, how to classify the entity, and how to submit the application by fax, mail, or other approved methods. You can read them on the official IRS Form SS-4 page. This page is only a helper for filling the PDF and does not replace the IRS instructions or any guidance from a tax professional.

You can also search for "Form SS-4 instructions" on the IRS website to confirm you are looking at the most recent information directly from the source before or after you complete your form here.

Where to get a blank or replacement Form SS-4

If you need a blank Form SS-4, you can download the current blank IRS Form SS-4 PDF directly from the Internal Revenue Service. This page helps you fill that official IRS PDF in your browser so it is ready for printing, signing, and submitting to the IRS using the methods described in the instructions.

If you need to correct information after an EIN has already been assigned, the IRS provides separate procedures for updating account details. The SS-4 used here is intended for requesting a new EIN, not for amending existing records.

Glossary of key terms on Form SS-4

Employer Identification Number (EIN)

An Employer Identification Number is a nine-digit number assigned by the IRS to businesses and certain other entities for tax administration purposes. It is used on federal tax returns, information returns, and other IRS filings in place of an individual's Social Security Number.

Responsible party

The responsible party is the individual who ultimately owns or controls the entity or exercises ultimate effective control. The IRS uses this person's identifying number on Form SS-4 to link the entity account to a real person for compliance purposes.

Disregarded entity

A disregarded entity is a business that is legally separate from its owner but is not treated as separate for federal income tax purposes. Single-member LLCs are often treated as disregarded entities. The SS-4 instructions explain how these entities should complete the form and whether a separate EIN is needed.

Principal activity

Principal activity refers to the main business area in which the entity operates, such as construction, retail, manufacturing, or professional services. On Form SS-4, the principal activity is indicated by checking an appropriate box on line 16 and describing the activity on line 17.

Security best practices when sharing a completed SS-4

Form SS-4 contains sensitive identifying information about both the entity and the responsible party. Even though the completed form is usually sent directly to the IRS, it may be stored in internal records or shared with advisors who assist with tax filings.

• Use secure methods such as encrypted email, secure portals, or fax lines when sending SS-4 information to trusted advisors or storage systems.
• Limit access to the completed form and EIN documents to people who need them for tax or administrative reasons.
• Keep copies of the completed SS-4 and the IRS confirmation notice in a safe place so you can reference them when opening accounts or filing returns.
• Confirm that any request for SS-4 data or EIN details is legitimate before sharing information, especially if the request arrives unexpectedly.

These are general security considerations. Always follow the specific instructions from the IRS and any guidelines from your tax or legal advisors.

Common questions people also ask about Form SS-4

• Is an EIN mandatory for every small business? Some very small operations can file under an individual's Social Security Number, while others need an EIN to open accounts, hire employees, or file specific returns. The IRS instructions to Form SS-4 provide examples of when an EIN is required.
• Can I cancel an EIN after getting it? The IRS can close an EIN account if a business is no longer active, but the number itself generally stays with the entity's history. The SS-4 application is used only to obtain a new EIN, not to cancel one.
• Do I need a new EIN if I change my business name? A simple name change does not always require a new EIN, but the IRS expects you to update their records. Whether a new EIN is needed depends on the type of change, and IRS publications give detailed examples.

FAQ about Form SS-4

Important disclaimer

This site is not affiliated with the IRS or any government agency. It provides a private tool that helps you fill the official IRS PDF in your browser. The information on this page is general and does not replace the official IRS instructions or professional advice. Always review your completed form and follow the IRS guidance and any advice from a qualified tax professional.