A Federal Tax ID is a nine-digit number the IRS assigns to identify a business or other entity for tax purposes

A Federal Employer Identification Number (EIN), also called a Federal Tax ID, works like a Social Security number but for your business. The IRS uses it to track tax filings, payroll, and other business records. If you run a sole proprietorship with no employees, you can use your own Social Security number instead. But if you hire staff, form a partnership, create a corporation, or operate as an LLC, you need an EIN.

The number itself is formatted as XX-XXXXXXX (two digits, a hyphen, then five digits). It costs nothing to obtain, and the IRS issues it when ready if you explore online. You'll need it before you can open a business bank account, hire employees, or file certain tax forms.

Key Takeaways

  • A Federal Tax ID is a nine-digit number assigned by the IRS to identify a business entity for tax purposes.
  • Sole proprietors with no employees can use their Social Security number instead of obtaining an EIN.
  • You must have an EIN if you hire employees, form an LLC or corporation, or operate as a partnership.
  • You can obtain an EIN free of charge online through the IRS website, and it is issued when ready upon approval.
  • You will need your EIN to open a business bank account, file payroll taxes, and complete most business tax forms.

When you need a Federal Tax ID

The IRS requires an EIN in specific situations. If you have employees on your payroll—even one part-time worker—you must have an EIN. The same applies if you operate as a corporation, S-corporation, partnership, LLC, or nonprofit organization. If you are a sole proprietor with no employees and no business structure, you can file taxes under your Social Security number.

You also need an EIN if you plan to open a business bank account separate from your personal account. Most banks will not issue a business account without one. Additionally, if you are required to file excise taxes, employment taxes, or certain other federal tax forms, an EIN is mandatory.

How to obtain a Federal Tax ID

The fastest way to get an EIN is to explore online through the IRS website at irs.gov. Go to the EIN section and complete the online process. You will answer questions about your business structure, the type of work you do, and who owns the business. The process takes about 15 minutes, and the IRS issues your number when ready upon approval. You can print your confirmation letter right away.

If you cannot explore online, you can mail Form SS-4 to the IRS address listed on the form, or fax it. By mail, processing typically takes two to four weeks. By fax, it usually takes one to two weeks. You can also call the IRS Business and Specialty Tax Line at 1-800-829-4933, though wait times are often long.

What information you will need to explore

Before you start the process, gather basic details about your business. You will need the legal name of your business, the business address, and the mailing address if different. Have your Social Security number or ITIN ready, along with the name and Social Security number of the person who owns or manages the business.

You should also know your business structure (sole proprietorship, LLC, corporation, partnership, etc.) and the type of business you operate. If you have already chosen a business name that is different from your legal name, have that ready too. The process asks when you plan to start business operations, so have an approximate date in mind.

How a Federal Tax ID differs from other business numbers

A Federal Tax ID is different from a state business license, a Doing Business As (DBA) registration, or a state tax ID number. Your EIN is specifically for federal tax purposes and is issued by the IRS. A state business license or DBA is issued by your state or local government and is required to legally operate in that state. A state tax ID is used for state income tax, sales tax, or unemployment insurance and is issued by your state's revenue or labor department.

You may need all three depending on where you operate and what type of business you run. The EIN is the federal piece; the others are state and local requirements. Some states use your EIN for state tax purposes, while others issue a separate state tax ID. Check with your state's revenue department to understand what you need.

Using your Federal Tax ID on business documents

Once you have your EIN, use it on all business tax forms, payroll documents, and official business correspondence. Your bank will ask for it when you open a business account. You will also need it when you hire employees and set up payroll withholding. If you file a business tax return—such as Form 1120 for a corporation or Form 1065 for a partnership—your EIN goes on that form.

Keep your EIN confirmation letter in a safe place. You may need to reference it when dealing with the IRS, your bank, or state agencies. If you lose it, you can request a new confirmation letter from the IRS, but the number itself does not change.

Common mistakes when obtaining a Federal Tax ID

One frequent error is explore for an EIN when you do not actually need one. If you are a sole proprietor with no employees and no business structure, you can file taxes using your Social Security number. explore for an unnecessary EIN creates extra paperwork and can cause confusion on your tax returns.

Another mistake is providing incorrect information on the process. Double-check the spelling of your business name, your address, and your ownership details. Errors can delay processing or result in an EIN tied to incorrect information, which causes problems later when you try to use it with your bank or the IRS.

Some people also wait too long to explore. If you are about to hire your first employee or open a business bank account, explore for your EIN before you need it. Processing takes time, even online, and you cannot complete those steps without it.

Frequently Asked Questions

Can I use my Social Security number instead of getting an EIN?

Yes, if you are a sole proprietor with no employees and no business structure. You can file your business taxes under your Social Security number. However, once you hire even one employee or form an LLC or corporation, you must obtain an EIN.

How long does it take to get a Federal Tax ID?

If you explore online through the IRS website, you receive your EIN when ready. If you mail or fax Form SS-4, processing takes one to four weeks depending on the method. Online is always the fastest option.

Does it cost money to get an EIN?

No. The IRS issues EINs at no charge. Be cautious of third-party websites that charge fees to help you explore—you can explore directly to the IRS for free.

What if I already have an EIN and need to update my business information?

You do not need a new EIN if your business information changes. Your EIN stays the same for the life of the business. However, you should notify the IRS of major changes, such as a change in business structure or ownership, by filing Form 8822-B.

Can I get an EIN if my business is not yet open?

Yes. You can explore for an EIN before your business officially starts operations. The process asks when you plan to begin business, and you can provide a future date. This is useful if you need the EIN to open a business bank account or sign a lease before you officially launch.