The fastest way to get an EIN number is the IRS online EIN Assistant at irs.gov, which issues your number on screen the moment you finish the application, at no cost. If your business is located in the United States or a U.S. territory and the responsible party has a Social Security number or Individual Taxpayer Identification Number, the whole process takes under fifteen minutes. Applicants without a U.S. presence, or anyone who can’t use the online tool, can get an EIN by phone (international only), by fax in about four business days, or by mail in around 30 days.
What to Have Ready Before You Start
The online application times out if you pause too long, so gather everything first. The IRS requires you to name a responsible party: the individual who owns or controls the entity and its funds. That must be a person, not another business, with a narrow exception for government agencies. You’ll enter their full legal name and their SSN or ITIN.1Internal Revenue Service. Responsible Parties and Nominees
Have the rest of this within reach:
- The legal business name exactly as it appears on your formation documents, such as articles of incorporation or an LLC operating agreement.2Internal Revenue Service. Instructions for Form SS-4
- The entity type: sole proprietorship, LLC, corporation, partnership, trust, estate, or another structure. You have to pick one.2Internal Revenue Service. Instructions for Form SS-4
- A physical mailing address. A P.O. box doesn’t qualify as your principal place of business.2Internal Revenue Service. Instructions for Form SS-4
- Your reason for applying, such as hiring employees, opening a bank account, or changing your business structure.3Internal Revenue Service. Employer Identification Number
Form SS-4 is the underlying application. Even if you plan to file online, downloading it and using it as a worksheet lets you line up every answer before the timer starts.4Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025)
Using an Accountant or Attorney
You can authorize a third party to apply on your behalf by naming them on Line 18 of Form SS-4. Their authority ends the moment the EIN is assigned, and the official confirmation still goes to the business address, not to them.4Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025) One catch: if the designee’s address or phone number matches the business’s, you can’t use the online tool and will need to file by fax or mail.
Applying Online: Number in One Sitting
The EIN Assistant walks you through prompts that mirror Form SS-4, validates your entries against federal records, and issues the EIN on the confirmation screen. Download and save the PDF right then; it’s your immediate proof of assignment. A formal confirmation notice (CP 575) arrives by mail in about four to six weeks. Keep both.
You can use the EIN immediately to open a bank account, apply for licenses, and file a paper tax return.3Internal Revenue Service. Employer Identification Number Electronic filing with a brand-new number may take extra time to clear IRS systems, so build in a buffer if a deadline is close.
Who Qualifies
Your principal place of business must be in the United States or a U.S. territory, and the responsible party needs a valid SSN, ITIN, or previously assigned EIN. Only one EIN is issued per responsible party per day.5Internal Revenue Service. Get an Employer Identification Number Setting up several entities? Spread the applications across consecutive days.
When the Tool Is Open
The online application isn’t 24/7, but the hours are wide:5Internal Revenue Service. Get an Employer Identification Number
- Monday through Friday, 6:00 a.m. to 1:00 a.m. the next day, Eastern Time
- Saturday, 6:00 a.m. to 9:00 p.m. ET
- Sunday, 6:00 p.m. to midnight ET
Outside those windows, you wait for the next session. The system also goes down for short maintenance windows, most often Sunday mornings.
If You Can’t Apply Online
Two alternatives beat mail by a wide margin.
Fax: About Four Business Days
Complete Form SS-4, include a return fax number, and send it to the office that matches your location. Under the IRS Fax-TIN program, you’ll generally receive your EIN by return fax within four business days.2Internal Revenue Service. Instructions for Form SS-4
- Within the 50 states or D.C.: 855-641-69356Internal Revenue Service. Where to File Your Taxes for Form SS-4
- International, faxing from within the U.S.: 855-215-16276Internal Revenue Service. Where to File Your Taxes for Form SS-4
- International, faxing from outside the U.S.: 304-707-94716Internal Revenue Service. Where to File Your Taxes for Form SS-4
Phone: International Applicants Only
If your business has no legal residence or principal office in the United States or its territories, call the IRS at 267-941-1099 and get your EIN during the call.2Internal Revenue Service. Instructions for Form SS-4 The line runs Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern Time. It’s not toll-free. The caller must be the responsible party or an authorized designee who can answer questions about the Form SS-4 information. For international applicants, this is the fastest route: you leave the call with the number.
Mail: About 30 Days
Mailed applications are processed in roughly 30 days.7Internal Revenue Service. Processing Status for Tax Forms Domestic filers send Form SS-4 to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. International filers send it to Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999.6Internal Revenue Service. Where to File Your Taxes for Form SS-4 Unless fax and internet are both unavailable to you, mail is the wrong choice when speed matters.
Free Means Free: Watch for Scam Sites
Applying through the IRS never costs anything.5Internal Revenue Service. Get an Employer Identification Number Even so, many websites charge up to $300 to fill out the same IRS form on your behalf. Some copy the agency’s logos, colors, and layouts, and use domain names containing “IRS” or “EIN Assistant.”
In April 2025, the Federal Trade Commission sent warning letters to operators of these sites, saying their practices may violate the FTC Act and the Impersonation Rule by posing as or implying affiliation with the IRS.8Federal Trade Commission. FTC Warns Operators of Websites that Charge for an Employer Identification Number and Claim Affiliation with the IRS Violations can carry civil penalties of up to $53,088 per offense and require consumer refunds. Check the address bar: if it doesn’t start with irs.gov, you’re not on the real application. If a site asks for payment before issuing an EIN, close the tab.
After You Get the Number
Save the PDF confirmation from the online session and file the CP 575 letter when it arrives by mail. Both serve as proof of your EIN to banks, licensing agencies, and payroll providers.
If you later misplace it, look at the original confirmation notice, your bank records, any state or local license filings, or a prior business tax return. If nothing turns 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. An agent will verify your identity and read the number back to you.3Internal Revenue Service. Employer Identification Number