How to get an EIN for your business: a step-by-step guide

What an EIN is

An employer identification number (EIN) is a nine-digit number the IRS assigns to a business, written like 12-3456789. It is the business's federal tax ID, the way a Social Security number is a person's. You put it on payroll returns, W-2s and 1099s, on your business tax return, and on the W-9 forms customers ask you to fill in. Banks ask for it when you open a business account, and state agencies ask for it when you register for payroll or sales tax.

Despite the name, you do not need employees to get one. Plenty of one-person businesses have an EIN. The number is free, it stays with the business for life, and the IRS never reuses it.

Not sure of the term? The glossary has a short entry on the EIN and the Canadian business number.

Who needs one

The IRS says you generally need an EIN to:

• Hire employees, even one part-time worker.
• Operate a partnership or corporation, including an LLC taxed as either.
• File excise tax returns or pay certain sales and excise taxes.
• Change the business structure or ownership, for example when a sole proprietorship incorporates.
• Administer certain trusts, retirement plans and estates.

A sole proprietor or single-member LLC with no employees and none of the situations above can usually use the owner's Social Security number instead. Even then, an EIN is often worth having: most banks want one for a business account, and it keeps your SSN off the W-9 forms that business customers ask you to fill in before they pay you.

If you have not yet decided between a sole proprietorship, an LLC or a corporation, read choosing a business structure in the US first. The structure decides what you put on the application, and an EIN issued for the wrong entity type is a nuisance to fix.

Before you apply

The online application has to be finished in one sitting. You cannot save it and come back, and it expires after 15 minutes of inactivity. Have this ready before you start:

• The entity is formed. If you are creating an LLC or corporation, file it with your state's secretary of state first and wait for the approval. The IRS warns that applying before the entity exists can delay the EIN.
• The legal name exactly as it appears on the formation documents, and any trade name (DBA) you use.
• The responsible party: the individual who ultimately owns or controls the business, with their name and SSN or ITIN. For most small businesses that is the owner or a principal officer.
• The mailing address and the physical location of the business, which must be in the United States or a US territory to apply online.
• The type of entity and, for an LLC, the number of members.
• The start date and the reason for applying (started a new business, hired employees, banking purposes and so on).
• Your main activity and what you sell, and whether you expect to have employees in the next 12 months and roughly how many.

Apply online, step by step

Online is the fastest route, and the number is issued at the end of the session. It is open Monday to Friday from 6 a.m. to 1 a.m., Saturday from 6 a.m. to 9 p.m., and Sunday from 6 p.m. to midnight, Eastern time.

1. Go to the IRS page "Get an employer identification number" on irs.gov and start the online application. Type the address yourself or follow the link from irs.gov. Look-alike sites charge a fee for the same free form.
2. Choose the type of entity: sole proprietor, partnership, corporation (including S corporation), LLC, estate, trust and others. For an LLC you are asked how many members it has and the state where it was formed.
3. Give the reason for applying. For a new business this is usually "Started a new business".
4. Enter the responsible party and confirm your role: the responsible party, or a representative they authorized.
5. Enter the business details: legal name, trade name, addresses, start date, accounting year-end month, industry and expected employees.
6. Choose how to receive the confirmation. Choose to view and download the letter online, so you have it straight away.
7. Review and submit. Check the legal name and entity type carefully. These are the details that cause trouble later.
8. Save the confirmation letter as a PDF and print a copy. Banks and state agencies may ask to see it.

The IRS issues one EIN per responsible party per day, so if you are setting up two entities, apply for the second one the next day.

You can use the new EIN straight away for most things, such as opening a bank account or filing a return by mail. For some electronic uses, including e-filing a return, the IRS says to wait up to two weeks while the number reaches all its systems.

Other ways to apply

• By fax: fill in Form SS-4 and fax it. Include a return fax number and the IRS faxes the EIN back in about 4 business days.
• By mail: send Form SS-4 to the address in its instructions. Allow about 4 weeks.
• By phone, for international applicants only: if the business's principal place of business is outside the United States, call 267-941-1099 (not toll-free), Monday to Friday, 6 a.m. to 11 p.m. Eastern time. Applicants outside the US without an SSN or ITIN use this route or fax.

After you have the number

1. Open the business bank account. Take the EIN letter, the formation documents and your ID. See how to open a business bank account.
2. Register with your state. If you will collect sales tax, register with the state tax department. If you will have employees, register for state income tax withholding (in states that have one) and for state unemployment insurance. Each state gives you its own account numbers.
3. Set up federal tax payments. Payroll tax deposits must be made electronically, usually through EFTPS. Enrol once you know you will run payroll.
4. Update your W-9. Give customers a W-9 with the EIN instead of your SSN. The Form W-9 page explains each line.
5. Put it in your books. Enter it in your accounting software's company settings so it appears on payroll forms and 1099s.
6. Keep the letter with your permanent records. If you lose the number, it is on prior tax returns and bank documents. The IRS Business and Specialty Tax Line can also look it up for an authorized person.

Common mistakes

• Paying for it. The EIN is always free on irs.gov.
• Applying before the LLC or corporation exists. Form it first, then apply.
• Choosing the wrong entity type. An LLC that wants to be taxed as an S corporation still applies as an LLC, then files Form 2553 for the election. The EIN application is not where you make the election.
• Getting a second EIN by accident. If the business already has one, use it. Two numbers for one entity confuse payroll filings and bank records.
• Letting the session time out. Gather everything first, then sit down and finish it.

Checklist

• Decide on the business structure
• Form the LLC or corporation with the state, if you are using one, and wait for approval
• Have the responsible party's name and SSN or ITIN ready
• Have the legal name, trade name, addresses, start date and year-end month ready
• Apply on irs.gov during the online hours, in one sitting
• Download and print the confirmation letter
• Open the business bank account
• Register with the state for sales tax, withholding and unemployment insurance as needed
• Enrol in EFTPS before the first payroll deposit
• Enter the EIN in your accounting software and on a fresh W-9

In AcboBooks

In AcboBooks the EIN goes in Company Settings, in the field labelled EIN / Tax ID. From there it is used on the W-2 file you upload to the SSA, and AcboBooks warns you if the EIN is blank when you create that file. When you are ready for payroll, the Academy lesson on setting up US payroll picks up where this guide ends. AcboBooks does not apply for the EIN or register you with the state; you do that on the government sites above.

Sources and official links

• IRS: Get an employer identification number (online application and hours)
• IRS: Employer identification number (fax, mail and international applicants)
• IRS: About Form SS-4, Application for Employer Identification Number
• IRS: Do you need a new EIN?
• EFTPS: Electronic Federal Tax Payment System
• SBA: Get federal and state tax ID numbers

Last reviewed October 26, 2026. Government pages change; if a figure here differs from the official page, the official page wins.

Frequently asked questions