FEIN vs. Tax ID: What's the Difference and Which One You Need

A FEIN and a tax ID are not the same thing, though the terms are often used interchangeably

A FEIN (Federal Employer Identification Number) is a specific nine-digit number issued by the IRS to businesses that have employees. A tax ID is a broader category that includes several types of identification numbers the IRS uses to track different entities. A FEIN is one kind of tax ID, but not all tax IDs are FEINs. The confusion happens because people often say "tax ID" when they mean "FEIN," and because a FEIN serves as your main tax identification number if you have employees.

The practical difference matters when you are filling out forms or talking to a bank or vendor. If someone asks for your "tax ID," they usually mean whatever number the IRS assigned to identify your business for tax purposes. If they specifically ask for a FEIN, they are asking for that nine-digit employer number. If you do not have employees, you may not have a FEIN at all—you might use your Social Security Number as your tax ID instead.

Key Takeaways

A FEIN is a nine-digit number the IRS issues only to businesses with employees; a tax ID is any identification number the IRS uses to track a business or individual for tax purposes.
If you are self-employed with no employees, you typically use your Social Security Number as your tax ID and do not need a FEIN.
Sole proprietors, partnerships, S-corps, and C-corps all need a FEIN if they have employees, regardless of business structure.
Banks, vendors, and government agencies may ask for "tax ID" when they specifically need your FEIN; clarifying which number they need prevents delays.

When you need a FEIN instead of just a tax ID

You need a FEIN if your business has employees on payroll. This includes full-time, part-time, and seasonal workers. The moment you hire someone and put them on your payroll, you must obtain a FEIN before you pay them, because you need it to file payroll tax returns with the IRS and to report wages to the Social Security Administration.

You also need a FEIN if you operate as a corporation (S-corp or C-corp) or a partnership, even if you have no employees. The IRS requires these business structures to have a FEIN for tax filing purposes. A sole proprietor with no employees can use their Social Security Number as their tax ID and does not need a FEIN, though they may choose to get one anyway.

Types of tax IDs and how they differ from a FEIN

The IRS recognizes several types of tax identification numbers. Your Social Security Number (SSN) is a tax ID if you are self-employed or a sole proprietor with no employees. A FEIN is the nine-digit number for businesses with employees or certain business structures. An Individual Taxpayer Identification Number (ITIN) is a tax ID for non-citizens who need to file taxes. An Employer Identification Number (EIN) is another name for a FEIN—the terms are used interchangeably by the IRS.

The key distinction is purpose. If you are filing taxes as an individual, your SSN is your tax ID. If you are running a business with employees or operating as a corporation or partnership, your FEIN is your tax ID. Banks and vendors often ask for "tax ID" because they need to know which number to use when reporting information about your account or transactions to the IRS.

How to learn about you have a FEIN

If you have employees or operate as a corporation or partnership, you should have received a FEIN when you registered your business. The IRS sends the FEIN by mail in a document called the SS-4 confirmation letter. Check your business records, your bank account paperwork, or any correspondence from the IRS. Your FEIN is a nine-digit number formatted as XX-XXXXXXX.

If you cannot find your FEIN, you can call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have your business name, address, and the approximate date you obtained the FEIN ready. The IRS can look it up for you. If you never obtained a FEIN but you have employees, you need to explore for one when ready through the IRS website or by mailing Form SS-4.

Situations where banks and vendors ask for a FEIN but call it a tax ID

When you open a business bank account, the bank will ask for your "tax ID." They mean your FEIN if you have one, or your SSN if you do not. When you hire a contractor and need to issue a 1099 form, you will ask them for their tax ID—which could be their SSN if they are self-employed, or their FEIN if they operate as a business with employees. When you explore for a business loan or line of credit, lenders ask for your tax ID to verify your business identity with the IRS.

The safest approach is to ask what number they need. Say: "Do you need my FEIN, or will my Social Security Number work?" This prevents confusion and ensures you provide the correct information. If you are unsure whether you have a FEIN, tell them you are self-employed with no employees and ask whether your SSN is sufficient.

How to obtain a FEIN if you do not have one

You can explore for a FEIN online through the IRS website at irs.gov. Go to the "explore for an EIN" section and complete Form SS-4 online. The process takes about 15 minutes, and the IRS issues your FEIN when ready. You can also print and mail Form SS-4 to the IRS, though this takes several weeks. Some tax professionals and accountants can file Form SS-4 on your behalf if you prefer.

You need your Social Security Number, business name, business address, and the date you started your business. Have your business structure ready (sole proprietor, partnership, S-corp, C-corp, LLC, etc.). If you are explore because you just hired your first employee, have the hire date ready. The IRS will ask why you are explore; select "Hired employees" or "Started a new business" as appropriate.

Frequently Asked Questions

Can I use my Social Security Number instead of a FEIN?

Yes, if you are self-employed with no employees and operate as a sole proprietor. Your SSN serves as your tax ID. However, if you have employees or operate as a corporation or partnership, you must have a FEIN. Some sole proprietors obtain a FEIN anyway for privacy reasons, since it keeps their SSN off business documents.

Is an EIN the same as a FEIN?

Yes. EIN stands for Employer Identification Number, and FEIN stands for Federal Employer Identification Number. The IRS uses both terms to refer to the same nine-digit number. You may see either term on IRS forms and documents.

What if I lost my FEIN confirmation letter?

Call the IRS at 1-800-829-4933 and provide your business name and address. They will look up your FEIN and read it to you over the phone. You can also create an IRS online account at irs.gov to view your FEIN and other business tax information anytime.

Do I need a FEIN if I am an LLC with no employees?

Not automatically. If your LLC is taxed as a sole proprietorship (single-member LLC), you can use your SSN as your tax ID. If your LLC is taxed as a partnership or corporation, or if you have employees, you need a FEIN. Check with your accountant or the state where you registered your LLC to confirm your tax classification.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.