EIN Number: What It Is, Why You Need One, and How to Get It
What an EIN number is, why your business needs one, and how to get one free from the IRS in minutes. A plain-English guide for owners.
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An EIN number is a nine-digit tax ID the IRS assigns to your business, and in most cases you can get one online in about 15 minutes, for free, directly from the IRS. That is the short answer. The longer answer, below, covers what the number actually does, whether you need one, and exactly how to apply without getting steered into a paid "filing service" you do not need.
This is a hub. If you already know the basics and just want a specific task, jump to the focused guides: what an EIN is, how to get an EIN, or how to find your EIN.
What is an EIN number?
An EIN - Employer Identification Number - is a unique nine-digit identifier (formatted as XX-XXXXXXX) that the Internal Revenue Service uses to recognize your business for tax purposes. Think of it as a Social Security Number for your company. It is also called a Federal Tax Identification Number or FEIN, and all three terms mean the same thing.
Despite the word "Employer" in the name, you do not need employees to get one. Sole proprietors, single-member LLCs, corporations, partnerships, nonprofits, estates, and trusts can all be assigned an EIN. The number stays with the business permanently and does not expire, even if the company goes dormant for years.
The key difference from your personal SSN: an EIN lets you keep business and personal finances separate. That separation matters legally and practically, especially once you form an LLC or a corporation, where mixing the two can undermine your liability protection.
Why do you need an EIN?
You are legally required to have an EIN if any of the following apply. According to the IRS, you need one if you:
- Have employees, or plan to hire them
- Operate as a corporation or a partnership
- File employment, excise, or certain other tax returns
- Withhold taxes on income paid to a non-resident alien
- Have a Keogh (retirement) plan
- Are involved with certain trusts, estates, or nonprofits
Even when it is not strictly required - for example, a solo sole proprietorship with no staff - an EIN is usually worth getting anyway. Here is why:
- Banking. Most banks require an EIN to open a business bank account for anything other than a sole proprietorship.
- Privacy. Vendors, clients, and payment processors often ask for a tax ID. Giving out an EIN instead of your SSN reduces identity-theft exposure.
- Credibility and credit. An EIN is the foundation for building a business credit profile and is frequently paired with a DUNS number when you apply for financing or trade accounts.
- Hiring. You cannot run payroll or hire employees legally without one.
If you are still at the planning stage - writing a business plan or registering the business - getting the EIN typically comes right after you form your legal entity and before you open a bank account.
How to get an EIN number
You can apply four ways. For nearly everyone with a U.S. presence, the online method is fastest and free.
1. Apply online (fastest - free, immediate)
If your business has a legal residence, principal place of business, or principal office in the United States or a U.S. territory, and the responsible party has a valid SSN or ITIN, apply through the IRS EIN Assistant at IRS.gov/EIN. You complete the interview in one session and receive the EIN immediately, ready to use.
A few things to know before you start:
- It is completely free. The IRS never charges for an EIN. Third-party sites that charge $50-$300 are simply filling out the same free form for you.
- Hours are restricted. Per the IRS Form SS-4 instructions, the online tool runs Monday-Friday 6 a.m.-1 a.m. ET, Saturday 6 a.m.-9 p.m. ET, and Sunday 6 p.m.-midnight ET.
- One per day. You can obtain only one EIN per responsible party per day.
- Finish in one sitting. The session times out after inactivity and does not save.
2. Apply by fax
Complete Form SS-4 and fax it to the IRS. Under the Fax-TIN program the IRS generally returns your EIN within about four business days, though processing has been slower in 2026 - often one to two weeks - due to reduced staffing. Fax is the standard route for applicants who cannot use the online tool.
3. Apply by mail
Mail a completed Form SS-4. This is the slowest option; allow several weeks. Use it only if you are not in a hurry.
4. Apply by phone (international applicants only)
If you have no legal residence or principal place of business in the U.S. - a common situation for non-resident owners of a U.S. LLC - you generally cannot use the online tool because the IRS cannot verify your responsible party against a U.S. tax record. International applicants can call the IRS at 267-941-1099 (not toll-free), 6 a.m.-11 p.m. ET, Monday-Friday, or fax Form SS-4 instead.
What you need before you apply
Have these ready so the application takes minutes, not hours:
- Legal name of the business and any trade/DBA name
- Business mailing and physical address
- The responsible party's name and SSN, ITIN, or existing EIN
- Type of entity (sole proprietor, LLC, corporation, partnership, nonprofit)
- Reason for applying (started a new business, hired employees, banking, etc.)
- Date the business started and the closing month of your accounting year
- Highest number of employees you expect in the next 12 months
The "responsible party" is the individual who ultimately owns or controls the business. For a single-member LLC, that is usually you.
Common EIN mistakes to avoid
- Paying for it. No legitimate reason exists to pay a third party. Go straight to the IRS.
- Getting more than one. Use a single method per entity so you do not accidentally end up with duplicate EINs.
- Applying too early. Form your legal entity first. If you are launching an LLC, do that with the state before requesting the EIN, so the details match.
- Losing the confirmation. Save the CP 575 confirmation notice the IRS issues. You will need the EIN for taxes, banking, and licensing, and it is easier to store than to retrieve.
- Confusing it with a state tax ID. An EIN is federal. Many states require a separate state tax or employer ID on top of it.
EIN and your broader setup
The EIN rarely stands alone. It typically slots into a sequence: choose a structure, register the business, get the EIN, then open banking and accounting. If you are early in that journey, these companion guides pair naturally with this one - how to start a business, how to register a business name, and how to get a business license. Once the EIN is in hand, you are cleared to open a business bank account and start operating properly.
Conclusion
An EIN is one of the cheapest, fastest, and most useful pieces of business infrastructure you will ever set up - free, immediate online, and permanent. If you have employees, a corporation, a partnership, or simply want to keep your personal SSN off business paperwork, get one. Apply directly at IRS.gov, keep the confirmation somewhere safe, and move on to the next step.
Ready to keep going? Line up your EIN alongside the rest of your launch checklist with our guide to starting a business and, when you are ready to formalize the structure, how to start an LLC.
Sources: IRS - Get an Employer Identification Number, IRS - About Form SS-4, IRS - Instructions for Form SS-4 (12/2025). This article is general information, not tax or legal advice; confirm requirements for your situation with the IRS or a professional.