How to Get a Business Tax ID Number (EIN)

To get a business tax ID number, apply directly with the IRS for an Employer Identification Number (EIN) using Form SS-4. It’s free, and the online application issues your nine-digit number on the spot once your information validates. Fax takes about four business days; mail takes four to five weeks.¹

Do You Actually Need One

The IRS requires an EIN if your business has employees, pays excise taxes, withholds taxes on payments to non-resident aliens, or operates as a corporation or partnership. Even outside those triggers, most banks want an EIN before they’ll open a business account, and many state licensing agencies ask for one too.²

Sole proprietors without employees can technically use their Social Security Number instead. There’s still a good reason to get an EIN: it keeps your SSN off the W-9s, 1099s, and other paperwork that pass through clients’ and vendors’ hands. The application takes a few minutes and costs nothing, so the tradeoff usually favors getting one.

What to Have Ready Before You Apply

Your entity has to exist under state or local law before you apply. Have your articles of organization, corporate charter, or partnership agreement in front of you, because the IRS asks for the legal name exactly as it appears on those documents.

Every application requires a responsible party: the individual who owns, controls, or exercises effective control over the entity and its funds. That person must supply a valid Social Security Number or Individual Taxpayer Identification Number. For most small businesses, this is the owner or managing member. The responsible party has to be an actual person; the IRS won’t accept another entity in the role.³

Your entity also needs a legal presence in the United States or a U.S. territory to use the online application. International applicants without a domestic address can still get an EIN, but by phone, fax, or mail instead.⁴

One more thing to plan around: the IRS issues only one EIN per responsible party per day, no matter which application method you use. If you’re setting up a holding company and a subsidiary at the same time, space the applications across separate days.⁵

How to Apply

Online: Same-Day

The IRS online EIN application is the fastest route. It’s free, walks you through the same questions as the paper form in a guided interview, and displays your EIN on screen once your information validates. You can download a confirmation and start using the number right away for banking, licensing, and paper tax filings.⁶

Application hours (Eastern time):

Monday through Friday: 6:00 a.m. to 1:00 a.m. the following day
Saturday: 6:00 a.m. to 9:00 p.m.
Sunday: 6:00 p.m. to midnight

Go directly to IRS.gov/EIN. If you land on a page asking you to pay, you’re not on the real IRS site.

Fax: About Four Business Days

If the online tool won’t work for you, fax a completed Form SS-4 to the IRS with a return fax number included. You’ll generally get your EIN back within four business days. Domestic and international applicants use different fax numbers; the international line is 304-707-9471.⁴

Mail: Four to Five Weeks

Mailed applications take roughly four to five weeks. Send your signed Form SS-4 to the address in the current instructions, and plan well ahead of anything that depends on having the number.⁴

Phone: International Applicants Only

If your entity has no legal presence in the U.S. or its territories, call the IRS at 267-941-1099 (not toll-free), Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern. Have a completed Form SS-4 in front of you before dialing, and make sure the caller is authorized to receive the EIN. The IRS may ask you to fax or mail the signed form within 24 hours after the call.²

What Form SS-4 Asks For

Whether you apply online or on paper, the questions are the same. Have answers ready for:

Legal name of the entity, exactly as it appears on your formation documents
Trade name (DBA), if different from the legal name
Mailing address where the IRS should send your confirmation letter
Entity type: corporation, LLC, partnership, sole proprietor, trust, estate, or another category
Responsible party’s full name and SSN or ITIN
Reason for applying: new business, hiring employees, banking, or another qualifying purpose
Business start or acquisition date and the closing month of your accounting year (usually December)
Expected number of employees over the next 12 months, if any

The form has an optional third-party designee section that lets an accountant or attorney receive the EIN on your behalf and answer IRS questions about the application. That authority is narrow and ends the moment the EIN is assigned; it doesn’t give the designee ongoing access to your tax account.⁴

After the EIN Is Issued

The IRS mails a confirmation notice called CP 575 to the address on your application. It lists your EIN, your entity’s legal name and filing address, and the federal tax forms you’re required to file. Keep it somewhere safe. Banks, state tax offices, and licensing agencies ask for it regularly.

You can start using the number immediately for most purposes if you applied online. One catch: it can take up to two weeks before a newly issued EIN is fully recognized in the IRS’s electronic filing systems, so if you need to e-file a return right away, you may have to wait or file on paper.

A federal EIN does not satisfy state tax registration. Most states that impose income, sales, or payroll taxes issue their own state tax ID through a separate process. Check with your state’s tax agency to find out what other registrations your business needs.⁷

One thing you won’t have to think about again: renewal. Once assigned, an EIN stays with that entity permanently. There’s no renewal cycle and no expiration.¹

Skip the Paid Services

You should never pay for an EIN. The IRS issues them free through its website, by fax, and by mail. Even so, third-party websites charge as much as $300 to file what is essentially the same form you can complete yourself in minutes, and many of them use IRS-like logos, color schemes, and phrases like “EIN Assistant” to imply government affiliation.⁸

The real application lives at IRS.gov/EIN. If a site asks for payment before issuing the number, it isn’t the IRS. The FTC has warned operators of these sites that impersonating a government agency can carry civil penalties exceeding $53,000 per violation, but new copycat sites keep appearing. Navigate directly to IRS.gov rather than clicking through search ads.

If You Lose the Number Later

Before calling the IRS, check the places your EIN likely already lives:

The CP 575 confirmation letter
Your business bank, which has it on file from account opening
State or local agencies where you applied for licenses
Prior-year business tax returns

If none of those turn it up, call the IRS Business and Specialty Tax Line at 800-829-4933, Monday through Friday, 7:00 a.m. to 7:00 p.m. local time. After verifying identity, they’ll provide the number over the phone to an authorized person.²

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Internal Revenue Service. Get an Employer Identification Number
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Internal Revenue Service. Employer Identification Number
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Internal Revenue Service. Responsible Parties and Nominees
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Internal Revenue Service. Instructions for Form SS-4 (12/2025)
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Internal Revenue Service. Instructions for Form SS-4 (12/2025)
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Internal Requi Service. Get an Employer Identification Number
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U.S. Small Business Administration. Get Federal and State Tax ID Numbers
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Federal Trade Commission. FTC Warns Operators of Websites That Charge for an Employer Identification Number and Claim Affiliation With the IRS