When you file taxes as an individual, your Social Security Number is used as a unique identifier that allows the IRS to tie all transactions and returns to you. A similar number is issued to each small business in the United States to allow for tax filing and other procedures to take place.

Unlike your Social Security Number, you may not know your Employer Identification Number (EIN) by heart, so it is important to know how to find this information and when to use this identifier.

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What is an EIN?

An EIN is an Employer Identification Number, which you may also hear referred to as a Federal Tax Identification Number or Federal Employer Identification Number. Like a Social Security Number, this is a nine-digit identifier that is unique to each business. The Internal Revenue Service is responsible for issuing these numbers and using them as a means of identifying businesses for tax reporting purposes.

In addition to the IRS, other business activities may require or at least strongly recommend the use of an EIN. Opening a business bank account, securing loans and other funding, and applying for certain licenses may all require you to provide a business EIN before proceeding.

Does every business need an EIN?

The IRS has specific rules surrounding who does and doesn’t need an EIN for their business. If any of the following criteria are met, an EIN is required:

  • Your business is a partnership
  • Your business is a corporation
  • Your business will file excise taxes
  • You have at least 1 employee, including a household employee
  • Your business withholds taxes for non-wage income paid to non-resident aliens

This means that the majority of businesses will need an EIN.

The primary exception is a sole proprietorship that does not have any employees. These businesses are able to obtain an EIN if they would like to for other purposes, but it’s not required. A single-member limited liability company (LLC) that does not meet any of the above criteria can also operate without an EIN.

Even if your business is not required to obtain an EIN, it can be helpful to have one. An EIN allows you to use an identifier other than your personal Social Security Number for business activities, which can protect against identity theft. Some business accounts and licenses will require an EIN, even if your business isn’t mandated to have one. Nearly any business credit card will also require an EIN. Because an EIN is free and easy to obtain, many sole proprietors choose to have one.

How do you get an EIN?

The process of getting an EIN is fairly simple and can be done through the IRS website. The agency provides a tool called the EIN assistant that operates during business hours, Monday to Friday from 7 AM to 10 PM. The new business owner or another responsible party can submit an application via the website, which will immediately provide you with an EIN upon completion.

If you prefer, you can also apply for an EIN by fax or mail by completing Form SS-4. The completed application can be sent to fax number (855) 641-6935 or mailed to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999.

The application will require you to share the type of business entity you are applying on behalf of, the number of owners, the state where your business is located, and why you are applying. You will also need to designate a “responsible party” or principal officer and provide their SSN or TIN and contact information.

How to find your company’s EIN

If you have already been granted an EIN and do not remember it, there are three primary places you can look for the number.

1. Check your EIN confirmation letter

When you first apply for and are granted an EIN, the IRS issues a confirmation letter. This letter contains your business tax ID and other identifying information for your business. Ideally, you would store this letter as you do other important tax documents and paperwork, especially if you applied by fax or mail and received a paper copy in return. If you file online, you should have received the letter immediately online.

Once you have located your letter, the EIN is typically listed at the top of the page, as well as in the first paragraph of the letter.

2. Check other paperwork

If you cannot find your EIN confirmation letter, there may be other documents in your possession that contain the information. Any old business tax returns or official notices from the IRS should contain your EIN in a prominent location. Many business licenses and permits will also display this number.

Bank account statements, business loan applications, and other financial documentation may also contain your EIN if it was used in association with the account. Your business credit report and even payroll paperwork may also be good places to look.

Remember that you must complete formation paperwork before you can obtain a tax identification number. This means that articles of incorporation, articles of organization, or fictitious name applications will not contain your EIN as it was not yet granted.

3. Contact the IRS

If you are unable to find your EIN number on any documents or archives of your own, the IRS can help you complete a federal tax ID lookup. The Business and Specialty Tax Line can be reached Monday through Friday from 7 AM Eastern to 7 PM Eastern. While the wait time can be very long, you will eventually be connected with a live representative who can provide your EIN over the phone.

Unlike a Social Security Number, a federal tax id number is often listed on public documents like a license and is not heavily secured, making it simple to get the information over the phone. However, they will still need to authorize your call and ensure that you can receive the information. You will need to answer questions that prove you are a corporate officer, sole proprietor, or partner in the business you are calling about.

Once you have located the number, put it in a safe place so that you can find it easily next time it is needed.

Does an EIN ever change?

Like a Social Security Number, an EIN is intended to represent a business throughout its entire lifespan. However, there are certain events that may require you to apply for a new EIN. These include:

  • Incorporating your company for the first time
  • Changing your business entity
  • Buying or inheriting an existing business
  • Your business became a subsidiary of another company
  • You are a sole proprietor who is subject to a bankruptcy proceeding
  • You are a sole proprietor and establish a pension, profit-sharing, or retirement plan
  • The state’s Secretary of State issues a new charter
  • Ownership structures change

The new EIN would replace your old one, so it would be used on all tax returns and business paperwork moving forward.

Once you have been assigned an EIN, the number is never used again. Even if a business closes down and never files a tax return, the number will not be used again in the future, and it could even be used if the same business reopened later. You can write a letter to officially close your business account through the IRS, but they will still not reissue the number.


Do I need an EIN if I am self-employed?

If you are self-employed, you can use your Social Security Number as an identifier when filing taxes instead of an EIN. However, it is often advised to use an EIN in order to reduce the risk of identity theft associated with your personal SSN. Keeping business and personal finances separate can offer additional protection in this way.

Can I look up another business’s EIN?

If you need to find an EIN for verification purposes and the company is not able to share it, you can use some public information to find the number. Public companies will have their EIN listed on their SEC filings as an “IRS No”. Credit bureaus and private EIN databases will also allow you to purchase access to other companies’ business information, including their EIN in some cases.

When should I get an EIN?

A business must be formed before you can apply for an EIN. That means that you should establish your business using the formal process in your state and for your type of entity first. Once you have a name and are able to operate, you can then apply for an EIN through the IRS. This should be done before you try to secure funding or open any business-related bank accounts and must be done before you can formally bring on any employees.

Is an EIN the same as a DUNS number?

An EIN is a nine-digit number issued by the IRS for tax reporting purposes. Dun & Bradstreet is a business analytics company that also issues nine-digit numbers to businesses. These are known as DUNS numbers, referring to the Data Universal Numbering System. The system helps businesses create and identify their credit reports.

What if I lose my EIN?

If you cannot locate your EIN on any paperwork or documents in your possession, the IRS EIN department will be able to assist. You can dial 1-800-829-4933 and speak to a live representative during business hours. Once they have confirmed your identity and association with the business, they can share your EIN.

What types of businesses need an EIN?

Nearly all types of businesses will need to obtain an Employer Identification Number through the IRS. Sole proprietorships that have no employees can operate under the owner’s personal Social Security Number, and single-member LLCs may also be able to do so. Any other business will need to have an EIN in order to file taxes in accordance with IRS guidelines.

Will I lose my EIN if I don’t use it?

No, EINs are issued only once. Even if a business dissolves or is not currently filing taxes, the number it was issued will remain associated. Business owners can write a letter formally letting the IRS know their business has been closed, but the same EIN will not be issued to another business.

Do I need a new EIN if I change my company’s name?

Changing the name of your business does not require you to obtain a new EIN. However, if the name change is associated with a change in ownership, structure, or the type of entity then you may need to apply for a new EIN through the IRS.

How long does it take to get an EIN?

Using the IRS website’s online EIN application and EIN assistant, you will receive an EIN and confirmation letter immediately after completing an application. You can opt to receive a paper copy in the mail in addition to the online version. You can immediately use this to open a bank account or apply for licenses. However, it can take up to two weeks for an EIN to become a part of the IRS’s permanent records.

Can I share my EIN with others?

An EIN is a matter of public record and can often be found by other individuals and businesses. They are not the same as Social Security Numbers and sharing your EIN does not put you at risk for identity theft. However, they should still be kept discrete to avoid anyone attempting to pose as your business or take any other malicious actions or commit fraud.

Is an EIN the same as a TIN?

A TIN is a tax-identification number. This refers to a nine-digit number issued by the IRS in order to track taxes. EINs meet these criteria and are a form of TINs. However, a Social Security Number is another kind of TIN. If you are asked for a TIN for your business, an EIN will serve this purpose.

Can foreign companies get an EIN?

Any business that may pay taxes or claim exemptions in the United States can obtain an EIN online. A foreign entity will need to complete the same application, Form SS-4, as domestic companies, but will need to provide the specific information requested on the form.