What is an EIN and how do you get one?

An EIN number is a crucial identifier for businesses to fulfill their US tax obligations, complete financial transactions, and run other basic operations – like hiring employees!

In our experience helping businesses comply with taxes around the world, we’ve learned all about the EIN and how important it is to stay compliant. So we decided to collect our research in one place!

In this post, you’ll learn:

• What is an EIN?
• What is an EIN used for?
• Do you need an EIN number for your business?
• How to apply for an EIN number
• What does an EIN look like?
• Where can you find your EIN number after you apply?
• What’s the difference between an EIN and a sales tax ID?
• Next steps after getting an EIN

What is an EIN?

An Employer Identification Number (EIN) — also known as a Federal Tax Identification Number — is a unique nine-digit number assigned by the United States Internal Revenue Service (IRS) to identify businesses and other entities for tax purposes. Issued by the federal government, the EIN serves as a critical tool for managing tax responsibilities. It also helps separate business and personal finances, supporting accurate bookkeeping, streamlined income tracking, and overall compliance with federal tax regulations.

In other words, this is a national level registration for businesses, whereas most other tax registration, such as acquiring sales tax permits and actually charging sales tax, are done at the state level.

To get an EIN, businesses can apply online through the IRS website, by mail, fax, or by phone. The specific instructions depend on whether you are located inside the US or somewhere else internationally. More on that in a section below!

What is an EIN used for?

Employer Identification Numbers are federal tax identifiers that the Internal Revenue Service — the US federal tax authority more lovingly known as the IRS — uses to identify your business and to track your business through various systems. An EIN number is legally required for your business to do a variety of things, such as file tax returns, open a business bank account, and even hire employees.

When it comes to taxes, EINs are only used for tax administration at the national level, which includes income tax but not sales tax. As we mentioned above, in the US, sales tax operates on a state and local level. You likely need to provide your EIN when you register for sales tax in a new state, but otherwise it is not involved with sales tax in the US.

What is an EIN for a business and do you need one?

Businesses, partnerships, corporations, non-profit organizations, and other entities are typically required to have an EIN. In fact, acquiring an EIN is often part of the process of forming a Limited Liability Company (LLC). In another article, we’ve covered the best states to form an LLC.

Sole proprietors may not need an EIN unless they have employees or choose to establish a retirement plan.

According to the US Small Business Administration and the IRS, your business needs an Employer Identification Number if you do any of the following inside the United States:

• Hire employees
• Pay employees
• Apply for credit or a loan
• Operate as a corporation or partnership
• File tax returns for employment, excise, or alcohol, tobacco, and firearms
• Withhold taxes on income, other than wages, paid to a non-resident alien
• Use a Keogh Plan (a tax-deferred pension plan)
• Work with certain types of organizations
  • Trusts, except certain grantor-owned revocable trusts and IRAs
  • Estates
  • Real estate mortgage investment conduits
  • Non-profit organizations
  • Farmers’ cooperatives
  • Plan administrators

Benefits of an Employer Identification Number

There are several practical and strategic advantages to obtaining an Employer Identification Number (EIN) for your business. First and foremost, an EIN is essential for filing federal taxes. It allows the IRS to track your business's tax obligations and filings accurately.

But beyond tax administration, an EIN is also a gateway to building business credit, as most lenders and credit bureaus require one to open credit lines in your business' name. This separation of personal and business finances not only protects your personal credit but also lends credibility to your business.

Additionally, an EIN is often required to open a business bank account, apply for certain licenses, and hire employees, making it a foundational step toward legal compliance and business growth. Whether you're forming an LLC, hiring your first team member, or planning for future expansion, having an EIN is a smart and sometimes necessary move.

What Are the Differences Between an EIN and Other ID Numbers?

When navigating business administration and tax filings, it's common to come across various identification numbers, and understanding how they differ is important. Here’s how an EIN compares to a TIN and a FEIN:

EIN vs. TIN

An Employer Identification Number (EIN) is actually a type of Taxpayer Identification Number (TIN). The term TIN is a broader category used by the IRS to refer to any number used for tax tracking purposes. This includes:

• Social Security Numbers (SSNs) – used for individual taxpayers
• Individual Taxpayer Identification Numbers (ITINs) – used for certain non-resident individuals and foreign nationals living in the U.S.
• Employer Identification Numbers (EINs) – used for businesses and other entities

So, every EIN is a TIN, but not every TIN is an EIN. If you're operating a business, your EIN is the TIN you’ll most often use.

EIN vs. FEIN

You might also see the term Federal Employer Identification Number (FEIN) used interchangeably with EIN. The key thing to know is: there is no difference between an EIN and a FEIN. Both refer to the same nine-digit number issued by the IRS to identify a business entity for federal tax purposes. The term “FEIN” simply emphasizes the federal nature of the number, but functionally, it’s the same as an EIN.

EIN vs. State tax ID

The tax systems on a state level are separate from the federal level. You’ll need a state tax ID to comply with local business tax rules. For instance, you need an EIN for federal income tax, and a state tax ID for state-level income tax (if the place where you live has it… 7 of them don’t!)

This is also a completely separate system from sales tax. Sales tax is a consumption tax that customers pay you when they make a purchase, similar to VAT or GST in other parts of the world. Then you must remit the money to the state government. Yep, US sales tax operates on a more local level, and sales tax rules vary by state.

How to apply for an EIN number

Applying for a Federal Tax Identification number is actually quite easy! It’s a free service through the IRS. In fact, the IRS warns that if you come across a site that’s charging you for the application, it might be a scam. To make the process more accessible, the IRS website provides instructions and application information in multiple languages, including English, Spanish, Chinese, Korean, Russian, Vietnamese, and Haitian Creole.

Here’s a breakdown of the process to get an EIN for a U.S.-based business.

Step 1: Determine Your Eligibility

Before applying, make sure your business is physically located in the United States or U.S. Territories. All applications will require the full name and Taxpayer Identification Number (SSN, ITIN, or EIN) of the main owner, or other roles such as the principal officer, general partner, grantor, or trustor. This person will be known as “the responsible party.”

Step 2: Compile Necessary Information

Before you begin your EIN application, gather all the required details to ensure a smooth process. You’ll need the following:

• Your business name – The legal name of the entity applying for the EIN.
• Responsible party's information – The full name and personal taxpayer identification number (SSN, ITIN, or EIN) of the principal officer, owner, or trustor.
• Type of business entity – Whether your business is a sole proprietorship, partnership, corporation, LLC, nonprofit, trust, estate, or another type.
• Reason for the EIN application– For example: starting a new business, hiring employees, opening a bank account, or changing your business structure.

Having this information ready ahead of time will help you complete the application quickly and accurately.

Step 3: Choose Your Application Method

You have a few options for applying, depending on how quickly you need your EIN and whether you prefer online or paper forms:

Option A: Apply for an EIN Online (This is the quickest route and the route that the IRS prefers.)

• Go to the IRS online application and “Apply for an EIN.”
• Complete the application in one session — your data won’t be saved if you close the window.
• Once validated, you should receive your federal business tax ID on the spot.
• Be sure to download and save your confirmation notice.

Option B: Apply by Fax

• Fill out IRS Form SS-4 carefully.
• Fax it to (855) 641-6935.
• If your form is complete and accurate, you’ll receive your EIN by fax within about four business days.

Option C: Apply by Mail

• Complete Form SS-4, correctly. Any mistakes will prolong the process by weeks or months, since paper processes are slower than digital.

• Mail it to the following address: Internal Revenue Service Attn: EIN Operation Cincinnati, OH 45999

• This method can take 4–6 weeks or longer, so plan ahead.

Step 4: Save Your EIN Confirmation

Regardless of the method you choose, be sure to keep a copy of your EIN confirmation letter or certificate. You’ll need it for tasks like opening a business bank account, applying for licenses, or filing taxes.

How to get an EIN if your business is based outside the US

If you have no primary business location, office, or legal residence in the US, then you’re considered an international business. Unfortunately you don’t have the option to apply online at this time.

Apply by phone

International businesses may call 267-941-1099 (not a toll-free number) to get a federal tax ID. Here are the hours for the phone service:

Monday through Friday 6 am - 11 pm (US Eastern Time)

The person making the call must be authorized to receive the number and answer questions from the Form SS-4.

It’s unclear from the IRS website how long this process lasts, but you can ask the agent helping you on the call.

Apply by fax or snail mail

To apply for EIN by fax or mail might be cheaper than an international phone call, plus you can do it on your own time. To apply by fax or mail, you must fill out the Form SS-4. Make sure all the required information is correct, to ensure the fastest processing time.

Once the Form SS-4 is complete, you should send it to the following:

Internal Revenue Service Attn: EIN International Operation Cincinnati, OH 45999

Fax: (855) 215-1627 (from within the US) or (304) 707-9471 (from outside the US)

Again, it’s unclear how long the international application process will take and when you will be assigned your federal tax ID. But generally the IRS says that an application by fax will take about 4 business days, while an application by mail will take about 4 weeks.

What does an EIN number look like?

An Employer Identification Number has 9 digits in the following format: XX-XXXXXXX. The two-digit prefix (XX) is the code that identifies the location or type of business entity. The last 7 digits identify your business in particular. And there is always a hyphen between the two sets.

For example, an EIN might look like: 12-3456789.

Where can you find your EIN number after you apply?

You may be able to find your EIN on a confirmation email from the IRS or previously filed forms, such as taxes or applications.

But if you’ve forgotten, lost or misplaced your number, no worries! Simply call the IRS Business and Specialty Tax Line at (800) 829-4933, and select EIN from the list of options. Once connected with an IRS employee, tell the agent you can’t remember it. The IRS employee will ask some security questions, then provide the number to you right there over the phone.

The IRS phone service hours are:

Monday through Friday 7:00 am - 7:00 pm (your local time, from wherever you’re calling in the US)

Next steps after getting an EIN

Once you’re done with the EIN number process, you might need to register for sales tax. Typically you must register your business in the state(s) where you’re located or where you have economic nexus. Once you’ve figured out where you’re liable, you can use our sales tax registration guides by state to apply for a seller’s permit.

When the time comes, Quaderno can help you stay compliant with local sales tax rules and grow your business with peace of mind. Give us a try for free.

How to Close Your Employee Identification Number

If your business is no longer operating and you won’t need your Employer Identification Number (EIN) in the future, it's important to properly close out your EIN with the IRS and other relevant authorities. Here's how to do it:

1. Cease Business Operations

The first step is to officially stop all business activity. This means completing any remaining work, notifying clients or vendors, and ensuring no new transactions or commitments are made under the business name or EIN.

2. File Final Tax Returns

Before you can close your EIN, you’ll need to file all required final tax returns:

• Federal income tax return with the box checked for “final return.”
• Employment tax returns (if you had employees), including Form 941 or Form 940.
• Sales tax returns if your business collected sales tax.

Be sure to pay any outstanding taxes and resolve any open tax issues with the IRS.

3. Cancel Your EIN With the IRS

Once your final tax obligations are met, send a formal letter to the IRS requesting to close your EIN account. Include:

• The legal name of your business
• The EIN
• The business address
• A statement that the business has ceased operations and the EIN is no longer needed

Mail this to:

Internal Revenue Service Cincinnati, OH 45999

Note: The IRS does not "delete" EINs — they remain permanently assigned. However, they can be closed and marked inactive.

4. Notify State and Local Authorities

Don’t forget to inform your state and local tax agencies that your business is shutting down. Requirements vary by state but often include:

• Final state income or franchise tax returns
• Final sales tax return
• Notice of business dissolution (for registered entities)

You may also need to dissolve your business entity through the Secretary of State.

5. Close Business Accounts

Shut down any business bank accounts, credit cards, or merchant service accounts associated with your EIN. Be sure all transactions have cleared and there are no pending charges or deposits.

6. Retain Records

Even after your business is closed, you should retain key business records — such as tax returns, employment records, and financial documents — for at least 3–7 years, depending on the type of records. This is important in case of audits or future legal questions.

7. Cancel Business Licenses and Permits

Finally, cancel any business licenses, permits, or registrations you held at the federal, state, or local level. This prevents future fees, renewals, or liabilities associated with inactive accounts.