How to Apply for an EIN: Everything You Need to Know
An Employer Identification Number (EIN) is one of the first things you need after forming a business. It is essentially a Social Security number for your company. The IRS uses it to identify your business for tax purposes, and banks, vendors, and state agencies will ask for it constantly.
The good news: applying for an EIN is free, and if you do it online, you can have one in about 15 minutes. This guide walks through exactly how to get one, which method to use, and the mistakes that trip people up.
What Is an EIN?
An EIN (also called a Federal Tax Identification Number or FEIN) is a unique nine-digit number assigned by the IRS. The format looks like this: XX-XXXXXXX.
The IRS assigns EINs to business entities for the purpose of tax administration. Think of it as your business's identity with the federal government. Every tax return, payroll filing, and business bank account ties back to this number.
An EIN is not the same as a state tax ID number. Many states issue their own identification numbers for state taxes, sales tax, and employer withholding. You will often need both.
Who Needs an EIN?
Not every business needs an EIN, but most do. Here is the breakdown:
You must get an EIN if your business:
- Has employees (or plans to hire)
- Operates as a corporation or partnership
- Files employment, excise, or alcohol/tobacco/firearms tax returns
- Withholds taxes on income paid to a non-resident alien
- Has a Keogh plan
- Is involved with trusts, estates, real estate mortgage investment conduits, nonprofits, or farmer cooperatives
You should get an EIN even if not strictly required if you:
- Operate as an LLC (even a single-member LLC)
- Want to open a business bank account (most banks require one)
- Need to build business credit separately from personal credit
- Want to avoid giving out your Social Security number to clients and vendors
- Plan to apply for business licenses or permits
You probably do not need an EIN if you:
- Are a sole proprietor with no employees and use your SSN for tax filings
- Have no plans to hire or open a separate business bank account
Even sole proprietors often get an EIN for privacy and professionalism. It is free, so there is little reason not to.
EIN Requirements by Business Type
| Business Type | EIN Required? | Notes |
|---|---|---|
| Sole Proprietorship (no employees) | No, but recommended | Can use SSN instead. EIN protects your personal SSN. |
| Single-Member LLC | No, but strongly recommended | Treated as a disregarded entity by default. Most banks require an EIN to open a business account. |
| Multi-Member LLC | Yes | Taxed as a partnership by default, which requires an EIN. |
| C-Corporation | Yes | Required for corporate tax filings and payroll. |
| S-Corporation | Yes | Needed before you can file Form 2553 for S-corp election. |
| Partnership | Yes | Required for partnership tax returns (Form 1065). |
| Nonprofit | Yes | Required for 501(c)(3) applications and tax-exempt status. |
| Estate or Trust | Yes | Required for fiduciary tax filings. |
Four Ways to Apply for an EIN
The IRS offers four methods to apply for an EIN. Each uses the same information (IRS Form SS-4), but they differ in speed and convenience.
1. Online Application (Recommended)
The IRS EIN online application is available at irs.gov/businesses/small-businesses-self-employed/apply-for-an-employer-identification-number-ein-online.
Processing time: Immediate. You get your EIN at the end of the session.
Availability: Monday through Friday, 7 a.m. to 10 p.m. Eastern Time.
Requirements:
- The responsible party must have a valid U.S. Taxpayer Identification Number (SSN, ITIN, or existing EIN)
- You must complete the session in one sitting (it times out after 15 minutes of inactivity)
- International applicants cannot use this method
This is by far the best option for most people. The application takes about 10 to 15 minutes, and you walk away with your EIN immediately. You can download the confirmation letter (CP 575) as a PDF.
2. Fax Application
Download Form SS-4 from the IRS website, fill it out, and fax it to the appropriate number:
- Domestic faxes: (855) 641-6935
- International faxes: (304) 707-9471
Processing time: 4 to 5 business days. The IRS will fax your EIN back to the number you provide.
Use this if the online system is down or if you prefer a paper trail.
3. Mail Application
Complete Form SS-4 and mail it to:
Internal Revenue Service
Attn: EIN Operation
Cincinnati, OH 45999
(International applicants mail to: Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999)
Processing time: 4 to 5 weeks.
There is almost no reason to use mail unless you have no other option. The wait time is significant.
4. Phone Application (International Applicants Only)
Call (267) 941-1099 (not a toll-free number). Available Monday through Friday, 6 a.m. to 11 p.m. Eastern Time.
Processing time: Immediate. The agent assigns your EIN during the call.
This method is exclusively for applicants who are not located in the United States and do not have a U.S. address.
Application Method Comparison
| Method | Processing Time | Best For | Limitations |
|---|---|---|---|
| Online | Immediate | U.S.-based applicants with SSN/ITIN | Must complete in one session; limited hours |
| Fax | 4-5 business days | Backup option; paper trail preference | Requires fax machine or online fax service |
| 4-5 weeks | Last resort | Very slow | |
| Phone | Immediate | International applicants only | Not available to U.S.-based applicants |
Form SS-4 Walkthrough: Line by Line
Whether you apply online, by fax, or by mail, you will answer the same questions from IRS Form SS-4. Here is what each section asks and how to fill it out correctly.
Lines 1-3: Business Name and Trade Name
- Line 1 - Legal name: The exact legal name of your entity as filed with your state. For an LLC, this is the name on your Articles of Organization. For a sole proprietorship, this is your personal legal name.
- Line 2 - Trade name/DBA: Only fill this in if your business operates under a different name than Line 1. For example, if your LLC is "Smith Holdings LLC" but you do business as "Smith Consulting."
- Line 3 - Executor/trustee name: Only applies to estates and trusts. Leave blank for LLCs and corporations.
Lines 4a-6: Address Information
Enter the mailing address and physical location of the business. If you are using a registered agent address, note that the IRS wants the principal business address, not the registered agent address. Use the actual location where the business operates.
Line 7a-b: Responsible Party
This is the most important section. The "responsible party" is the person who controls, manages, or directs the entity and the disposition of its funds and assets.
- For a single-member LLC, this is the sole member.
- For a multi-member LLC, this is typically the managing member.
- For a corporation, this is a principal officer (president, CEO, etc.).
- For a sole proprietorship, this is the owner.
The responsible party must provide their SSN or ITIN. You cannot use another EIN here.
Line 9a: Type of Entity
Select the entity type that matches your business:
- Sole proprietor - individual owner, no separate entity
- Partnership - two or more owners, including multi-member LLCs taxed as partnerships
- Corporation - includes both C-corps and S-corps
- LLC - check this and indicate the number of members
If you have formed an LLC and plan to elect S-corp taxation, select LLC here. The S-corp election is a separate filing (Form 2553) that you do after getting your EIN.
Line 10: Reason for Applying
Common reasons include:
- Started new business - most common for new LLCs and corporations
- Hired employees - if an existing business is hiring for the first time
- Banking purpose only - if you need the EIN solely to open a bank account
- Changed type of organization - if you converted from a sole proprietorship to an LLC
Lines 11-13: Business Start Date and Closing Month
- Line 11: The date the business was started or acquired. For new entities, use your formation date.
- Line 12: Closing month of your accounting year. Most small businesses use December (calendar year).
- Line 13: Highest number of employees expected in the next 12 months. Enter zero if you do not plan to hire. Break it down by agricultural, household, and other employees.
Lines 14-18: Employment Tax and Activity Details
These lines ask about expected employment tax liability, principal business activity, and specific products or services. Answer honestly based on your actual plans. If you are not sure about expected payroll, estimate conservatively.
What to Do After You Get Your EIN
Getting the EIN is just the first step. Here is what to do next:
1. Save your confirmation letter (CP 575). This is the official IRS document confirming your EIN. Store a digital copy and keep a hard copy somewhere safe. You cannot get a duplicate of the CP 575, only a verification letter (147C) if you lose it.
2. Open a business bank account. Most banks require your EIN, formation documents, and operating agreement (for LLCs) to open an account.
3. Register for state taxes. Your EIN covers federal taxes only. Most states require a separate registration for state income tax withholding, sales tax, or unemployment insurance.
4. Set up payroll if you have employees. You will need the EIN for all employment tax filings (Forms 941, 940, W-2s).
5. File your S-corp election if applicable. If you plan to be taxed as an S-corp, file Form 2553 within 75 days of formation or by March 15 for the current tax year.
6. Use it on contracts and W-9 forms. When clients or vendors request a W-9, provide your EIN instead of your personal SSN.
Common EIN Application Mistakes
These are the errors that cause applications to get rejected or delayed:
1. Mismatched Business Name
The name on your EIN application must exactly match the name on your state formation documents. If your Articles of Organization say "Acme Solutions LLC" but you apply as "Acme Solutions," the IRS may flag it. Double-check spelling, punctuation, and whether "LLC" is included.
2. Wrong Responsible Party
The IRS is strict about who qualifies as the responsible party. It must be an individual (not another business) with a valid SSN or ITIN. Listing someone who is not actually involved in the business can cause problems down the road.
3. Applying Before State Formation Is Complete
Your LLC or corporation must be officially formed with the state before you apply for an EIN. If you apply too early and your state filing gets rejected or your name changes, you will end up with an EIN tied to an entity that does not exist.
4. Applying Multiple Times
Each entity only needs one EIN. If you are not sure whether you already have one, call the IRS Business & Specialty Tax Line at (800) 829-4933 before applying again. Having multiple EINs for the same entity creates confusion with tax filings.
5. Not Completing the Online Application in One Session
The online application times out after 15 minutes of inactivity. Have all your information ready before you start. If it times out, you have to begin again from scratch.
6. Using the EIN Before the IRS Database Updates
Even though you get your EIN immediately online, it can take up to two weeks for the number to appear in the IRS database. During this window, electronic tax filings may be rejected. If you need to file immediately, file a paper return.
Frequently Asked Questions
Does an EIN expire?
No. Once assigned, an EIN belongs to that entity permanently, even if the business closes. You cannot cancel, reuse, or reassign an EIN.
Can I apply for an EIN if I do not have an SSN?
You need a valid U.S. Taxpayer Identification Number (SSN or ITIN) to be the responsible party. If you are a foreign national without an SSN, apply for an ITIN first, then use it to apply for the EIN by phone or fax.
How much does an EIN cost?
Nothing. The IRS does not charge any fee to apply for or receive an EIN. If a website is charging you for an EIN application, you are paying a third-party service, not the IRS. You can always apply directly for free.
Do I need a new EIN if I change my business structure?
It depends. If you convert from a sole proprietorship to an LLC, you generally need a new EIN. If you change from an LLC to a corporation, you also need a new one. But if you simply elect S-corp taxation for an existing LLC or corporation, you keep the same EIN.
Can a single-member LLC use the owner's SSN instead of an EIN?
Technically yes, for tax purposes. A single-member LLC is a disregarded entity by default, meaning it files on Schedule C of the owner's personal return. But practically, you still need an EIN to open most business bank accounts, and using your SSN on invoices and W-9s exposes your personal information. Get the EIN.
Bottom Line
Applying for an EIN is free, fast, and necessary for almost every business. The online application is the clear winner for anyone with a U.S.-based taxpayer identification number. You can complete it in 15 minutes and walk away with your EIN immediately.
Here is the short version:
1. Make sure your business is officially formed with your state
2. Gather your information (legal name, address, responsible party SSN, entity type)
3. Go to the IRS EIN online application
4. Complete Form SS-4 step by step
5. Save your CP 575 confirmation letter
6. Open your business bank account and register for state taxes
Do not pay a third-party service to do this for you. It is free and straightforward directly through the IRS.
This article is for educational purposes only and does not constitute legal or tax advice. Consult a qualified attorney or CPA for guidance specific to your situation.