A FEIN (Federal Employer Identification Number) is a unique nine-digit number the IRS assigns to businesses operating in the United States for tax and payroll identification purposes.

Think of it as a Social Security Number — but for your business.

It is formatted like this: XX-XXXXXXX

What Is a FEIN and What Does It Stand For

FEIN stands for Federal Employer Identification Number.

It is issued by the Internal Revenue Service (IRS) and used to identify your business on tax returns, payroll records, and government filings.

Some people also call it:

• EIN (Employer Identification Number)
• Federal Tax ID Number
• Business Tax ID

They all refer to the same number.

The IRS uses your FEIN to track your business’s tax obligations, payroll taxes, Social Security contributions, and Medicare premiums.

In 2026, the IRS continues to require all eligible businesses to maintain an active and accurate FEIN on all federal and state filings.

How a FEIN Works as a Tax Identifier for Your Business

Your FEIN is the core identity of your business in the eyes of the federal government.

Here is how it works in practice:

Purpose	How FEIN Is Used
Payroll Processing	Identifies your business when filing payroll taxes
Tax Returns	Required on all federal business tax filings
W-2 Forms	Listed in Box B on every employee’s W-2
Bank Accounts	Banks require it to open a business account
Business Contracts	Used to verify your business identity

Some states also require a separate state EIN or Employer Account Number (EAN) in addition to your federal FEIN.

Always check your state’s specific requirements to stay fully compliant.

Which Businesses Are Required to Have a FEIN in the United States

Not every business needs a FEIN — but most do.

You are required to get a FEIN if your business:

• Has one or more employees
• Operates as a corporation or partnership
• Files employment, excise, alcohol, tobacco, or firearms tax returns
• Withholds taxes on income paid to a non-resident alien
• Has a Keogh plan (tax-deferred pension plan)

These organizations also require a FEIN:

• Non-profit organizations
• Estates and trusts
• Farmers’ cooperatives
• Real estate mortgage investment conduits
• Plan administrators
• Individual Retirement Accounts (IRAs) in certain cases

Who does NOT need a FEIN?

A sole proprietor with no employees typically does not need one. The IRS will use the owner’s Social Security Number (SSN) as the business tax ID instead.

If you own multiple businesses, each one that qualifies needs its own separate FEIN.

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How to Apply for a FEIN Through the IRS Step by Step

Applying for a FEIN is completely free. The IRS does not charge any fee.

You can apply in three ways:

1. Online (Fastest — Recommended)

• Visit the official IRS website
• Complete the online application
• Your FEIN is issued immediately upon completion
• You can download, save, and print it right away
• Note: The session expires after 15 minutes of inactivity

2. By Fax

• Complete IRS Form SS-4
• Fax it to the IRS number for your location
• Receive your FEIN within 4 business days if you include a return fax number

3. By Mail

• Complete IRS Form SS-4
• Mail it to the IRS EIN Operations office in Cincinnati, OH
• Processing takes up to 4 weeks

What you need before applying:

• Legal name of the business
• Business structure (LLC, corporation, sole proprietor, etc.)
• Name and Taxpayer ID of the responsible party
• Business address and start date

Important in 2026: The IRS allows only one FEIN application per responsible party per day, regardless of the method used.

When Your Business Needs to Get a New FEIN

Not every business change triggers the need for a new FEIN — but some do.

You need a new FEIN when:

• Ownership of the business changes significantly
• A sole proprietorship converts to a corporation or partnership
• A partnership is dissolved and a new one is formed
• A business goes through a merger or acquisition that changes its legal structure

You do NOT need a new FEIN when:

• You simply change your business name
• You move to a new address
• You make internal changes like restructuring departments or shifting management roles

Business structure changes are the key trigger — not cosmetic ones.

When in doubt, consult a tax attorney or CPA before making any assumption. Getting this wrong can create IRS compliance issues that are costly to fix.

FAQ’s

What is the difference between a FEIN and a tax ID number?

A tax ID number is a broad term that covers several types of identifiers — including SSNs and ITINs for individuals. A FEIN is specifically for businesses and entities that employ workers or file certain business tax returns.

Is a FEIN the same as an EIN?

Yes. FEIN and EIN refer to the same number. The “F” in FEIN simply emphasizes that it is issued at the federal level.

Is a FEIN public information?

Yes, in many cases. Publicly traded companies have their FEIN visible in SEC filings. It may also be shared in business-to-business transactions. However, the IRS advises business owners to use discretion to prevent fraud.

Where is the FEIN on a W-2 form?

Your employer’s FEIN appears on your W-2 form in Box B, just above the employer’s name and address.

Does a FEIN expire?

No. A FEIN does not expire and does not need to be renewed. Once assigned, it belongs to your business permanently — unless a structural change requires a new one.

What if I am not sure whether I need a FEIN?

The IRS provides an online FEIN questionnaire on its website. If you answer yes to any of the questions, you need a FEIN. You can also consult a licensed tax professional or CPA for personalized guidance.

Conclusion

Understanding your FEIN definition and requirements is one of the most fundamental steps in running a legally compliant business in the United States. Get it right from the start, and it will save you significant time, money, and stress down the road.