What an EIN actually is
An Employer Identification Number is a nine digit federal tax ID the IRS issues to a business or organization, the equivalent of a Social Security number for an entity rather than a person. Plenty of small operations never need one at all, and plenty of people apply for one anyway because a bank asks for it, which is a choice rather than a legal requirement.
Who the IRS actually says needs one
irs.gov states the list plainly, and the checker above runs on it directly rather than a paraphrase of it: "Generally, you need an EIN to: Hire employees. Operate a partnership or corporation. Pay sales and excise taxes. Change business structures or ownership. Administer certain trusts, retirement plans and estates." Any one of those on its own is enough. None of them mention how big the business is or how much it makes.
The trap that catches the most people runs the other way round from what they expect. Forming a single member LLC feels like the moment a business becomes official, so it feels like the moment an EIN becomes compulsory. It is not. Left in its default tax treatment, a single member LLC is a disregarded entity for federal tax purposes, and with no employees and no excise tax to pay, the owner can carry on filing under their own Social Security number. Electing to have that same LLC taxed as a corporation flips the answer immediately, with nothing changing at the state level at all, because the entity is then operating as a corporation in the IRS's own terms.
Running the other way, a sole trader with no staff can still trip one of the other conditions: paying excise tax, or changing the structure or ownership of the business, both apply whatever the headcount is. "I have no employees" answers only the first item on a five item list.
The process itself, and why it is worth doing directly
Apply on IRS.gov and, if the application is approved, the number is issued immediately in the same session. The online tool is open Monday to Friday from 6 a.m. to 1 a.m. the following day, Saturday 6 a.m. to 9 p.m., and Sunday 6 p.m. to midnight, all Eastern time, and it allows one EIN per responsible party per day. The session expires after 15 minutes of inactivity, which matters more than it sounds, because starting again means re-entering everything. Have the responsible party's Social Security or individual taxpayer ID number ready first. A business whose principal location sits outside the United States cannot use the online tool at all, and applies instead using Form SS-4 by phone, fax or mail.
Never pay for this
The IRS's own page is direct about it: "Beware of websites that charge for an EIN. You never have to pay a fee for an EIN." On 1 April 2025 the FTC sent warning letters to operators of websites selling EIN filing and delivery services, some charging consumers up to $300 for something the IRS gives away free and immediately, warning that creating a false impression of affiliation with the IRS may violate the FTC Act and the Impersonation Rule. A site that looks official, uses IRS colors, or ranks near the top of a search is not the same thing as being the IRS. The genuine application only ever lives at IRS.gov.
A checklist against the published reasons, not a filing
This is a checklist, not a filing service. It tells you whether the IRS's own published reasons apply to you and points you at the free, official process, but it does not submit anything on your behalf, and it cannot see your details because nothing you type leaves your browser. Where a trust, an estate, or a business structure genuinely sits in a gray area, that is worth a few minutes with an accountant rather than a guess, because the responsible party named on an EIN application is the person the IRS holds accountable afterwards.
Common questions
Is an EIN really free?
Yes, always. The IRS's own page states it plainly: "Beware of websites that charge for an EIN. You never have to pay a fee for an EIN." Apply directly on IRS.gov and, if the application is approved, the number is issued immediately, at no cost. Anywhere charging a fee is charging for something the federal government hands over free.
Does forming an LLC automatically mean I need an EIN?
No. A single member LLC that has not elected to be taxed as a corporation is a disregarded entity for federal tax purposes, which is the trap most people fall into. With no employees and no excise tax to pay, it can use the owner's own Social Security number instead of a separate EIN. That changes the moment the LLC hires anyone, starts paying excise tax, or elects corporate tax treatment, at which point it lands squarely on the IRS's own list of reasons you need one.
I am a sole trader with no staff. Am I definitely in the clear?
Usually, but not always. The IRS's list of reasons applies whatever your headcount is: paying sales and excise taxes, or changing your business structure or ownership, both trigger the need for an EIN on their own. A sole trader with no staff and neither of those happening genuinely does not need one and can carry on using their own Social Security number.
How quickly can I actually get one?
If you apply online and the application is approved, the EIN is issued immediately, in the same session. The online tool is open Monday to Friday from 6 a.m. to 1 a.m. the next day, Saturday 6 a.m. to 9 p.m., and Sunday 6 p.m. to midnight, all Eastern time. It allows one EIN per responsible party per day, and the session times out after 15 minutes of inactivity, so it helps to have your details ready before you start.
My business is based outside the United States. Can I still apply online?
No. The online application is only for businesses whose principal location is in the United States or a US territory. Everyone else applies using Form SS-4, by phone, fax or mail, which takes longer but is still entirely free.
Does a nonprofit need an EIN even before it has any income?
Yes. A nonprofit needs its own EIN to open a bank account, to file its own returns, and because one has to be included on the application for recognition of tax-exempt status. None of that depends on the organization having taken in a single donation yet.
What about a trust or an estate?
Most need their own EIN to be administered, which is the IRS's own fifth reason on the list: "administer certain trusts, retirement plans and estates." The commonly missed exception is some grantor trusts, which can carry on using the grantor's own Social Security number while the grantor is alive. Check that specific point before assuming a trust needs its own number.
What do I need ready before I start the application?
The Social Security number or individual taxpayer ID of the responsible party, meaning whoever actually controls the entity rather than a nominee, plus the legal name and mailing address of the business and a decision on which entity type you are applying as. Getting the responsible party right matters: it is who the IRS holds accountable for the entity afterwards.