EIN and Tax ID are not the same thing, though the terms are often used interchangeably

An EIN (Employer Identification Number) is a nine-digit number issued by the IRS to identify a business entity for tax purposes. A Tax ID is a broader category that includes several types of identification numbers — EIN is one of them, but so are Social Security Numbers (SSN), Individual Taxpayer Identification Numbers (ITIN), and Adoption Taxpayer Identification Numbers (ATIN). When someone says "Tax ID," they might mean any of these, depending on context.

The confusion arises because many people use "Tax ID" as shorthand for "business tax ID," which is usually an EIN. But technically, every person and business has a tax ID of some kind. If you are a sole proprietor with no employees, your SSN functions as your tax ID. If you run a corporation, partnership, or LLC, you need an EIN as your tax ID.

Key Takeaways

  • EIN is one specific type of tax ID issued by the IRS; Tax ID is the umbrella term for all identification numbers used for tax reporting.
  • Sole proprietors without employees can use their Social Security Number as a tax ID, but many choose to get an EIN instead.
  • Businesses structured as corporations, partnerships, LLCs, or S-corps must obtain an EIN and cannot use a personal SSN.
  • An EIN is free to obtain and takes about 15 minutes to apply for online through the IRS website.
  • You will need an EIN to open a business bank account, hire employees, or file certain business tax returns.

When you need an EIN instead of just a Tax ID

You must obtain an EIN if your business is structured as a corporation, partnership, LLC, or S-corporation. The IRS requires these entity types to have a separate business identifier distinct from the owners' personal tax IDs. You also need an EIN if you plan to hire employees, even as a sole proprietor, because the IRS uses the EIN to track payroll taxes and withholdings.

Many sole proprietors without employees choose to get an EIN even though they are not required to. This is often done to keep business and personal finances separate, to protect privacy (since you would not have to share your SSN with vendors or clients), or to make it easier to hire contractors or employees later without having to reapply.

How to obtain an EIN

You can apply for an EIN online through the IRS website at no cost. The online application takes about 15 minutes and you receive your EIN immediately upon completion. You will need your business name, business address, the type of business structure, and the name and SSN or ITIN of the owner or responsible party.

If you prefer not to apply online, you can mail Form SS-4 to the IRS, fax it, or call the IRS Business and Specialty Tax Line at 1-800-829-4933. Mail applications typically take four weeks. Fax applications take about two weeks. Phone applications are processed immediately, but you must have all required information ready before you call.

What documents you need to provide

For an online EIN application, you will need to provide your legal name, date of birth, and SSN or ITIN. You will also need your business name (if different from your legal name), the business address, and a description of what the business does. If you are applying on behalf of a business entity rather than as an individual owner, you will need the name and SSN of the person with authority to sign for the business.

No documents need to be uploaded or mailed with an online application. The IRS verifies your information in real time. If you apply by mail or fax, you do not need to send supporting documents unless the IRS requests them after reviewing your application.

How EIN and Tax ID appear on your tax forms

If you are a sole proprietor using your SSN as your tax ID, you report your business income on Schedule C (Profit or Loss from Business) attached to your personal Form 1040. Your SSN appears in the identification section of the return.

If you have an EIN, you use that number on all business tax forms, including Form 1040-ES (quarterly estimated tax payments), Form 1065 (partnership returns), Form 1120 (corporate returns), and Form 941 (payroll tax returns). Your SSN still appears on the return as the owner, but the EIN is the primary business identifier.

EIN, Tax ID, and business bank accounts

Most banks require an EIN to open a business bank account, even if you are a sole proprietor. Some banks will accept an SSN, but this is becoming less common. Having a separate business bank account is important because it makes tax reporting easier and provides a clear record of business income and expenses for the IRS.

If you have an EIN, bring the EIN letter from the IRS to the bank along with your personal ID, proof of address, and any business formation documents (such as articles of incorporation or an LLC operating agreement). If you are opening an account as a sole proprietor using your SSN, the bank will ask for your personal ID and proof of address.

Frequently Asked Questions

Can I use my Social Security Number as a tax ID for my business?

Yes, if you are a sole proprietor with no employees. Your SSN functions as your tax ID for business purposes. However, you cannot use an SSN if your business is structured as a corporation, partnership, or LLC — those entities must have an EIN.

Do I need an EIN if I am self-employed but have no employees?

No, you are not required to have an EIN. You can use your SSN as your tax ID and report self-employment income on Schedule C. Many self-employed people get an EIN anyway to keep business and personal finances separate and to protect their privacy.

How long does it take to get an EIN?

Online applications are processed immediately and you receive your EIN right away. Mail applications take about four weeks. Fax applications take about two weeks. Phone applications are processed during the call if you have all required information ready.

What is the difference between an EIN and an ITIN?

An ITIN (Individual Taxpayer Identification Number) is issued to individuals who do not have an SSN, such as nonresident aliens or certain dependents. An EIN is issued to businesses. Both are types of tax IDs, but they serve different purposes and are issued to different entities.

Can I change my EIN after I receive it?

No. An EIN is permanent and does not change. If you change your business structure (for example, from sole proprietor to LLC), you will need to obtain a new EIN. The old EIN remains associated with your previous business structure.