You need an EIN from the IRS, not a separate "tax ID"

An LLC does not get a special tax ID. Instead, the IRS issues you an Employer Identification Number (EIN), which functions as your tax ID for federal purposes. The EIN is a nine-digit number formatted as XX-XXXXXXX. You use it on tax returns, bank accounts, and any document that asks for a tax ID.

The IRS issues EINs free of charge. You do not pay a fee to request one, and no private company can charge you for obtaining an EIN — though many do, which is why understanding the direct route matters.

Whether you actually need an EIN depends on your LLC structure. A single-member LLC taxed as a sole proprietorship can use your Social Security Number instead. A multi-member LLC, an LLC taxed as a corporation, or an LLC with employees must have an EIN. Most LLCs get one anyway because banks often require it to open a business account.

Key Takeaways

  • An EIN is a nine-digit number issued free by the IRS and serves as your LLC's federal tax ID.
  • Single-member LLCs can use their owner's Social Security Number for tax purposes, but most banks require an EIN to open a business account.
  • You can request an EIN online through the IRS website in minutes, by mail, by fax, or by phone — online is fastest and requires no documents.
  • The IRS processes online requests when ready and issues the number on the spot; mail and fax requests take four weeks.
  • You do not need to form your LLC with the state before requesting an EIN, though having your formation documents ready helps if you explore by mail.

How to request an EIN online (fastest route)

The IRS website at irs.gov has a tool called the EIN Assistant that lets you request an EIN when ready. You answer questions about your business, your name, your address, and your ownership structure. The entire process takes about 10 minutes.

You do not upload documents or prove anything. The IRS does not verify your LLC formation at this stage. You straightforward provide your information, submit, and receive your EIN on screen. You can print or save the confirmation page, which shows your new number.

The online tool is available Monday through Friday, 7 a.m. to 10 p.m. Eastern Time. It is not available on weekends or federal holidays. If you miss the window, you can try again the next business day or use one of the other methods below.

Other ways to request an EIN if online does not work

If you cannot use the online tool, the IRS accepts EIN requests by mail, fax, or phone. Each method has different timing and document requirements.

By mail: Fill out Form SS-4 (process for Employer Identification Number) and mail it to the IRS address listed on the form. Processing takes about four weeks. You can include a copy of your LLC formation documents (the Articles of Organization filed with your state), though it is not required.

By fax: Complete Form SS-4 and fax it to the IRS fax number listed on the form. The IRS typically responds within four business days. This method is faster than mail but slower than online.

By phone: Call the IRS Business and Specialty Tax Line at 1-800-829-4933. You will speak to an agent who asks the same questions as the online form. They issue your EIN over the phone and mail a confirmation letter. This takes one business day.

What information you need before you request

Regardless of which method you use, have the following information ready: your LLC's legal name (exactly as it appears on your state formation documents), the address where your LLC is located, your name and Social Security Number, the name and address of the LLC's owner or managing member, and a description of what your business does.

You also need to know your LLC's start date or the date you expect it to start operating. If you have not yet filed your Articles of Organization with the state, you can still request an EIN — use the date you plan to file or the date you expect to begin business.

If your LLC has a different mailing address than its physical location, have both ready. The IRS will ask which one to use for correspondence.

Do you need to form your LLC first?

No. You can request an EIN before your LLC is officially formed with the state. Many business owners request the EIN while their Articles of Organization are still being processed by the state.

However, the IRS will ask for your LLC's legal name and your state of formation. If you have not yet filed with the state, use the name you plan to file and the state where you plan to form the LLC. The IRS does not verify formation at the time of EIN issuance.

If your LLC name changes after you receive your EIN, or if you form in a different state than you stated, contact the IRS to update your EIN record. This is a straightforward process but worth doing to keep your records aligned.

Using your EIN for a bank account and tax filings

Once you have your EIN, you can open a business bank account. Most banks require an EIN or a Social Security Number. Bringing your EIN confirmation page and your Articles of Organization (or a copy) speeds up the process.

You will also use your EIN on your federal tax return. The form depends on your LLC structure: a single-member LLC taxed as a sole proprietorship files Schedule C with Form 1040; a multi-member LLC files Form 1065 (partnership return); an LLC taxed as a corporation files Form 1120. Your accountant or tax software will tell you which form applies to your situation.

If you have employees, you use your EIN to file payroll tax returns and to register for state unemployment insurance. If you do not have employees, you still use it on your annual federal return and on any state tax forms that ask for it.

Common mistakes to avoid

The most common mistake is paying a third party to get your EIN. Websites and services advertise "EIN registration" or "EIN filing" and charge $50 to $300 for something the IRS provides free. You do not need them. Go directly to irs.gov or call the IRS.

Another mistake is requesting an EIN before deciding on your LLC structure. If you think your LLC might be taxed as a corporation or a partnership, decide that first. The IRS asks about your business structure during the EIN request, and changing it later requires a new EIN in some cases.

Do not confuse an EIN with a state tax ID. Some states issue separate tax identification numbers for sales tax, income tax, or other purposes. An EIN is federal only. Check your state's tax authority website to see if you need a state tax ID in addition to your EIN.

Frequently Asked Questions

Can I use my Social Security Number instead of an EIN?

If your LLC has only one owner and is taxed as a sole proprietorship, yes — you can use your SSN on your tax return. However, most banks require an EIN to open a business account, so you will likely need one anyway. Getting an EIN does not cost anything, so most single-member LLC owners get one for convenience.

How long does it take to get an EIN?

Online requests are processed when ready — you receive your number on screen. Phone requests take one business day. Fax requests take about four business days. Mail requests take about four weeks. If you need your EIN quickly, use the online tool or call the IRS.

What if I already have an EIN from a previous business?

You cannot reuse an old EIN for a new LLC. Each business entity gets its own EIN. Request a new one through the same process. The IRS will not issue a duplicate EIN for the same business, but it will issue a new one for a different entity.

Do I need to file anything with the state after I get my EIN?

No. An EIN is federal only. You still need to file your Articles of Organization with your state to officially form your LLC, but that is a separate process. The EIN and state formation are independent — you can do either one first.

What if the IRS rejects my EIN request?

Rejections are rare when you explore online. If it happens, the IRS will tell you why — usually because the information did not match IRS records or because of a data entry error. Try again with corrected information, or call the IRS Business and Specialty Tax Line for help.