The short answer
An EIN (Employer Identification Number) is a free nine-digit federal tax ID that the IRS issues to businesses. As of October 2026, the IRS says U.S. applicants can request one on IRS.gov and, if the application is approved, receive the number immediately; faxing Form SS-4 takes about 4 business days and mailing it about 4 weeks. The IRS says it never charges a fee for an EIN.
This article is general information for founders, not legal, tax, or financial advice. Rules, fees, and filing requirements vary by state and change over time. Nothing here creates a professional relationship of any kind. Confirm anything that affects your business with your state's filing office and a qualified attorney or accountant before you act on it.
Hiring employees, forming an LLC or corporation, and a few other situations lead to the same piece of federal paperwork: an Employer Identification Number from the IRS. The IRS runs the whole process, and its own pages are the reference for every detail below. This guide describes how the process works in order, where the IRS’s instructions differ by type of business, and what the application asks for. Every IRS statement was checked against the IRS’s pages on October 1, 2026, and the sources are listed at the end.
State filings come before or after the EIN depending on whose list is followed. For one state’s version of the whole sequence, with fees and forms, see the Nevada startup guide.
What is an EIN?
An EIN is a nine-digit federal tax ID number, written like 12-3456789, that the IRS assigns to sole proprietors, corporations, partnerships, estates, trusts and other entities for tax filing and reporting. The IRS says it is for use in connection with business activities only, and is not a substitute for a Social Security number (SSN) or an individual taxpayer identification number (ITIN). The IRS lists opening a bank account, applying for business licenses and filing a tax return by mail among the things an EIN can be used for right away.
Is an EIN the same as a tax ID number?
In everyday use, yes. The IRS says an EIN is also known as a federal tax identification number. “Tax ID” can still point to other numbers, though, because the IRS’s own umbrella term is the taxpayer identification number (TIN), and an EIN is one of five kinds. A state’s tax and license numbers are separate again. The table sets out the numbers people most often mix up.
| Number | What it identifies | Issued by | What the sources say |
|---|---|---|---|
| EIN | A business entity, plus estates and trusts that report income on Form 1041 | The IRS | The IRS says an EIN is also known as a federal tax identification number. |
| FEIN | The same number as an EIN | The IRS | The Nevada Department of Taxation says a federal identification number is also called an Employer Identification Number (EIN or FEIN). |
| TIN | An umbrella term for the numbers the IRS uses to administer the tax laws | The Social Security Administration (SSNs) or the IRS (all others) | The IRS lists the SSN, EIN, ITIN, ATIN and PTIN as taxpayer identification numbers. |
| SSN | A person | The Social Security Administration | The IRS says an EIN is for business activities only and is not a substitute for an SSN. |
| ITIN | An individual who cannot get an SSN, such as certain nonresident and resident aliens, their spouses and dependents | The IRS | The IRS describes it as a nine-digit number beginning with 9, and says an EIN is not a substitute for it. |
| State tax ID | A business's account with a state agency, such as a tax permit or license ID | A state agency, where the state requires one | Separate from the federal EIN, and it varies by state. The Nevada Department of Taxation, for example, lists an EIN, a business license and tax permits as three separate steps. |
The IRS’s page on these numbers also lists the ATIN, a temporary number for people in the process of adopting a child, and the PTIN, which paid tax preparers must use on the returns they prepare.
Who needs an EIN?
The IRS’s overview says an EIN is needed for a business that has employees, that will pay employment, excise or alcohol, tobacco and firearms taxes, or that withholds taxes on income other than wages paid to a nonresident alien. It also lists the entities that need one to operate: partnerships, LLCs, corporations, tax-exempt organizations, estates, trusts (except certain grantor-owned revocable trusts), retirement plans and IRAs, real estate mortgage investment conduits, and farmers’ cooperatives. The table below sets out how that reads for the situations founders most often ask about.
| Situation | What the IRS says about an EIN |
|---|---|
| The business has employees | The IRS lists having employees among the reasons an EIN is needed. |
| It pays employment, excise, or alcohol, tobacco and firearms taxes | The IRS lists these taxes among the reasons an EIN is needed. |
| It operates as a partnership, corporation or LLC | The IRS lists these entities as ones that need an EIN to operate. For single-member LLCs, see the next row. |
| A single-member LLC with no employees and no excise tax liability | The IRS’s single-member LLC page says such an LLC, treated as a disregarded entity, does not need an EIN for federal tax purposes, and can still apply for one, for example to open a bank account or where state tax law requires one. The same page says most new single-member LLCs will need one. |
| A sole proprietor with no employees | The IRS says a business that does not need an EIN for federal tax purposes can still request one for banking or state tax purposes. |
| A change in ownership or business structure | The IRS says that, in general, a new EIN is needed when ownership or structure changes. |
The IRS adds that EINs are not meant for other activities, such as state tax lien auctions, sales or lotteries.
The ways to apply for an EIN
The IRS recommends applying online if possible, and says to use only one method for each entity so that it does not receive more than one EIN. The IRS also limits issuance to one EIN per responsible party per day, whatever the method.
- Online Immediately once the application is approved For applicants whose principal place of business is in the U.S. or a U.S. territory
- Fax About 4 business days when a fax number is given for the reply Form SS-4, for applicants whose principal place of business is in the U.S.
- Mail About 4 weeks by return mail Form SS-4, for applicants whose principal place of business is in the U.S.
All three are free. Applicants whose principal place of business is outside the U.S. use the phone, fax or mail routes described below instead.
Sources: IRS, Employer identification number and IRS, Instructions for Form SS-4, both opened October 1, 2026.
| Way to apply | Who it is for | Timing, per the IRS | Details |
|---|---|---|---|
| Online at IRS.gov | Applicants whose principal place of business is in the U.S. or a U.S. territory, with a responsible party who has an SSN or ITIN | The EIN is issued immediately online if the application is approved | One session; it cannot be saved and expires after 15 minutes of inactivity |
| Fax Form SS-4 | Applicants whose principal place of business is in the U.S. | About 4 business days, if a fax number is given for the reply | Fax to 855-641-6935; the IRS says fax numbers can change without notice |
| Mail Form SS-4 | Applicants whose principal place of business is in the U.S. | Approximately 4 weeks | Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999 |
| Phone | Applicants whose principal place of business is outside the U.S. only | The number is assigned during the call | 267-941-1099, Monday to Friday, 6 a.m. to 11 p.m. Eastern; the IRS says it no longer issues EINs by phone to domestic applicants |
Applicants outside the U.S. can also fax Form SS-4 to 855-215-1627 (from within the U.S.) or 304-707-9471 (from outside the U.S.), or mail it to Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999. The IRS says high inventory levels may delay paper applications and points to its processing status page for tax forms. For a mailed application, the Form SS-4 instructions give 800-829-4933 to verify a number or ask about status.
How to get an EIN online, step by step
What follows is the order the IRS’s pages suggest, written as a typical sequence rather than a required one. The IRS’s online application is the reference for what it actually asks.
1. Register the entity with the state first (LLCs and corporations)
The IRS says that when creating a corporation or LLC, the entity is formed through the secretary of state before the EIN application, and that if it is not formed with the state first, the application may be delayed. The business name entered on the application is the name as it appears on the registration or formation documents. A sole proprietorship is an unincorporated business, so there is no state formation to complete first. How to start a business in Nevada shows where that filing sits in one state’s sequence, and the LLC formation checklist covers the same stages in general terms.
2. Identify the responsible party
The application names a responsible party: the person who owns or controls the entity, or exercises ultimate effective control over it, and who manages its funds and assets. The IRS says the responsible party must be a person, not an entity, unless the applicant is a government entity, and the application gives that person’s SSN or ITIN. The IRS also says nominees, meaning people given limited authority to act for the entity while it is being formed, cannot apply for an EIN and are not listed on Form SS-4. The online tool can be used by the responsible party or by an authorized representative, and a third-party designee needs signed authorization to apply.
3. Gather the details the application asks for
The lines on Form SS-4, the paper version of the application, show the kinds of details the IRS collects:
| Detail | What the Form SS-4 instructions say |
|---|---|
| Legal name | Entered exactly as it appears on the formation or other legal document. A sole proprietor enters their own name here, not the business name. |
| Trade name | The “doing business as” (DBA) name, if different from the legal name. |
| Addresses | A mailing address, and a physical street address only if different. The street address cannot be a P.O. box. |
| County and state | Where the principal business is located. |
| Responsible party | Full name and SSN or ITIN. |
| LLC details | Whether the applicant is an LLC and how many members it has, plus the type of entity. |
| Reason for applying | One box, such as started a new business, hired employees or banking purpose. |
| Start date | The date the business started or was acquired. |
| Accounting year | The closing month of the accounting or tax year. A calendar year closes in December. |
| Employees | The highest number expected in the next 12 months, and the first date wages were paid, if any. |
| Business activity | The principal activity and a more detailed description of the line of business. |
The online tool’s own screens are the reference for what it asks. The IRS says business names in its systems can use only letters, numbers, hyphens and ampersands: symbols such as plus signs or periods are spelled out or replaced with a space, slashes become hyphens, and apostrophes are removed. Street addresses are limited to 35 characters, and the IRS points to USPS standard abbreviations.
4. Open the application and finish it in one session
The IRS’s online tool is available during these hours, in Eastern Time (as of October 2026):
- Monday to Friday, 6:00 a.m. to 1:00 a.m. the next day
- Saturday, 6:00 a.m. to 9:00 p.m.
- Sunday, 6:00 p.m. to midnight
The IRS says the application is completed in one session, cannot be saved for later, and expires after 15 minutes of inactivity, after which it has to be started over. It also says only one EIN can be requested per responsible party per day. The tool is on the IRS’s page for getting an employer identification number.
5. Keep the confirmation
The IRS’s page lists “print your EIN confirmation letter for your records” among how the tool works, and the Form SS-4 instructions say online applicants can view, print and save the EIN assignment notice at the end of the session. The IRS also describes three ways to confirm an EIN later: request an entity transcript, download a digital CP575 notice from a Business Tax Account (for eligible users), or call the business and specialty tax line and ask for Letter 147C, which is the letter for an EIN previously assigned.
6. Start using the EIN
According to the IRS, the EIN can be used immediately for most business needs, including opening a bank account, applying for business licenses and filing a tax return by mail. Some uses wait up to 2 weeks: passing the IRS’s TIN Matching Program, e-filing a tax return, and making tax deposits or paying electronically. If a return is due before the EIN arrives, the IRS says to write “Applied For” and the application date in the space for the number.
How much does an EIN cost, and how long does it take?
An EIN costs nothing from the IRS. The IRS’s page says the tool issues an EIN for free, and also says to beware of websites that charge for one, because an EIN never requires a fee.
On timing, the IRS says an online application that is approved is issued immediately. By fax, with a fax number provided, the reply generally takes about 4 business days. By mail the EIN arrives in approximately 4 weeks, and the Form SS-4 instructions say to complete a mailed form at least 4 to 5 weeks before the number is needed.
How to get an EIN for an LLC
The IRS treats an LLC as a corporation, a partnership or part of its owner’s tax return, depending on the number of members and on any election it files. A domestic LLC with at least two members is classified as a partnership for federal income tax purposes unless it files Form 8832 and elects to be treated as a corporation, and a single-member LLC is treated as a disregarded entity unless it makes the same election. For employment tax and certain excise taxes, the IRS treats a single-member LLC as a separate entity that uses its own name and EIN.
The Form SS-4 instructions say how the LLC lines are marked:
- A single-member LLC classified as a disregarded entity checks “Other” on the entity-type line and writes “disregarded entity.”
- A domestic LLC with two or more members that accepts the default partnership classification checks “Partnership.”
- An LLC that files Form 8832 or Form 2553 to be taxed as a corporation checks “Corporation” and writes the form number of the return it will file.
The instructions also say that the entity-type line is not an election of tax classification. For the order of steps in practice, the IRS says to form the LLC with the state first. Forming an LLC out of state describes what changes when the state of formation and the state of operation differ.
Where the EIN sits in a state’s startup order
State and local pages do not agree on where the EIN goes. In Nevada, for example, the Department of Taxation’s start page lists the EIN first, the IRS tells LLC and corporation filers to register with the state first, and the City of Las Vegas lists the state business license before the EIN. The Nevada startup guide follows the IRS’s instruction for LLCs and places the EIN after the state filing, and says where the sources differ.
How to get an EIN as a sole proprietor
The IRS describes a sole proprietor as someone who owns an unincorporated business by themselves. The Form SS-4 instructions say a sole proprietor generally files one Form SS-4 and needs only one EIN, regardless of the number of businesses or trade names. On the form, a sole proprietor enters their own name on the first line and the business name, if there is one, as the trade name. The “sole proprietor” box is described as for filers of Schedule C or Schedule F who have a qualified plan, are required to file excise, employment, alcohol, tobacco or firearms returns, or pay gambling winnings. The IRS also says a sole proprietorship that incorporates or enters into a partnership needs a new EIN. LLC vs. sole proprietorship compares how the two structures are formed and filed.
When is a new EIN needed, and what if it is lost?
A new EIN. The IRS says that, in general, a new EIN is needed when an entity’s ownership or structure changes, and that a new EIN is not needed to change the business name, address or responsible party. Changes in the responsible party are reported on Form 8822-B within 60 days. The IRS says a business entity should have only one EIN, and it gives 800-829-4933 (TTY 800-829-4059) for anyone who has more than one and is unsure which to use.
A lost EIN. The IRS lists these places to look: the notice issued when the EIN was assigned, the bank that holds the business account, agencies where state or local licenses were applied for, and past business tax returns. If the number still cannot be found, the IRS gives 800-829-4933, Monday to Friday, 7 a.m. to 7 p.m. local time (Pacific time for Alaska and Hawaii). The IRS says it verifies identity and can give the number over the phone to someone authorized to receive it.
An EIN that is no longer needed. The IRS says it cannot cancel an EIN, but can deactivate it.
What this guide leaves out
- Tax treatment. Which tax forms and elections apply to a given business is outside this guide. It repeats what the IRS says about how an LLC is classified and does not say which classification suits anyone.
- State and local registrations. A state tax registration or a city or county license is a separate process from the federal EIN. The Nevada startup guide lays out one state’s version.
- Other kinds of entities. Trusts, estates, nonprofits, retirement plans, government entities and applicants whose principal place of business is outside the U.S. have their own rules on the IRS’s pages, which this guide only touches.
- Beneficial ownership reporting. The IRS’s EIN pages also point to FinCEN’s beneficial ownership information reporting page. Whether that applies to a given company is a separate question that FinCEN’s own site answers.
- Age. This guide is written for adult founders. The responsible party on an application has to be a person with an SSN or ITIN, and how the rules apply to someone under 18 is a legal question this article does not answer.
Frequently asked questions
How do I get an EIN?
A U.S. applicant typically completes the IRS's free online application in a single session on IRS.gov, naming the entity type, the business name and a responsible party with a Social Security number or ITIN. As of October 2026, the IRS says an approved online application is issued an EIN immediately. Form SS-4 can instead be faxed (about 4 business days) or mailed (about 4 weeks). The IRS's pages are the reference for current steps.
Is an EIN the same as a tax ID number?
In everyday use, yes. The IRS says an EIN is also known as a federal tax identification number, and that it identifies a business entity. The IRS's broader term, taxpayer identification number (TIN), covers the EIN, the Social Security number, the ITIN and two special-purpose numbers. A state's tax or license ID is a separate number issued by a state agency. A form's instructions say which kind of number it asks for.
Is an EIN free?
Yes. The IRS says an EIN is free when requested directly from the IRS, and that no fee is ever required for one. Its EIN page warns about websites that charge for an EIN. The IRS's own online application, fax number and mailing address are the free routes, and the IRS's EIN page is the usual starting point for all three.
How long does it take to get an EIN?
As of October 2026, the IRS says an EIN is issued immediately when an online application is approved. If Form SS-4 is faxed with a fax number provided, the IRS says the EIN comes back in about 4 business days, and a mailed form takes approximately 4 weeks. The IRS adds that high inventory levels can delay paper applications.
Do I need an EIN for an LLC?
The IRS lists LLCs among the entities that need an EIN to operate, and its single-member LLC page says most new single-member LLCs will need one. That page also says a disregarded single-member LLC with no employees and no excise tax liability does not need one for federal purposes, though it can get one, for example for a bank account. The IRS says to form the LLC with the state first.
Do I need an EIN?
The IRS says an EIN is needed to hire employees, to pay employment, excise, or alcohol, tobacco and firearms taxes, and to operate entities such as partnerships, corporations and LLCs. A business that does not need one for federal tax purposes can still request one for banking or state tax purposes. Whether an EIN applies to a specific business is a question for the IRS or a tax professional.
What do I need to apply for an EIN?
The IRS's online application asks for the entity type and a responsible party, meaning the person who owns or controls the entity, along with that person's Social Security number or ITIN. Form SS-4 also collects the legal name, addresses, reason for applying, start date and expected employees. The IRS says the business name entered is the name on the formation documents, and the responsible party must be a person, not an entity, unless the applicant is a government entity.
Can I get an EIN without a Social Security number?
The IRS's online application requires the responsible party to have a valid SSN, ITIN or EIN. Applicants whose principal place of business is outside the U.S. can apply by phone, fax or mail instead. Form SS-4's instructions say to enter "foreign" or N/A on the taxpayer ID line if the responsible party has no SSN or ITIN and is ineligible to get one. The IRS's current instructions are the reference.
What if I lose my EIN?
The IRS lists several places to look: the notice it issued when the EIN was assigned, the bank that holds the business account, agencies where state or local licenses were applied for, and past business tax returns. If the number still cannot be found, the IRS gives 800-829-4933, Monday to Friday, 7 a.m. to 7 p.m. local time, where it verifies identity and can give the number to authorized callers.
This article is general information for founders, not legal, tax, or financial advice. Rules, fees, and filing requirements vary by state and change over time. Nothing here creates a professional relationship of any kind. Confirm anything that affects your business with your state's filing office and a qualified attorney or accountant before you act on it.
Keep reading
- How to start a business in Nevada: the steps, state fees and forms for one state, with the EIN in its place in the order.
- The LLC formation checklist: the same stages in general terms, for any state.
- LLC vs. sole proprietorship: how the two structures are formed and filed, described without recommending one.
- The best states to start a business in 2026: taxes, filing fees and formation speed across five states.
- The founders we have profiled: young founders, verified before they are featured.
- How this publication works: who writes these guides and how figures are sourced.
- IRS, Get an employer identification number (page reviewed Aug. 19, 2026), opened October 1, 2026.
- IRS, Employer identification number (page reviewed Jul. 17, 2026), opened October 1, 2026.
- IRS, Instructions for Form SS-4 (revised 12/2025), opened October 1, 2026.
- IRS, Single member limited liability companies (page reviewed Jul. 27, 2026), opened October 1, 2026.
- IRS, Responsible parties and nominees (page reviewed Aug. 22, 2026), opened October 1, 2026.
- IRS, Sole proprietorships (page reviewed Jun. 28, 2026), opened October 1, 2026.
- IRS, About Form SS-4, Application for Employer Identification Number, opened October 1, 2026.
- IRS, Taxpayer identification numbers (TIN) (page reviewed Jun. 11, 2026), opened October 1, 2026.
- Nevada Department of Taxation, Start / Run a Business, opened October 1, 2026.
Last verified: October 1, 2026. The IRS changes its pages, phone numbers and processing times from time to time, so the IRS's own site is the reference. This article is educational, not legal or tax advice.