Getting an EIN takes ten minutes and costs nothing

Two facts do most of the work on this page. The IRS issues EINs free — its own guidance says you never have to pay a fee for one — and it issues them immediately through an online application that takes about ten minutes. There is no expedited tier, no processing queue to jump and nothing to buy.

The second fact is that a lot of money is made from people not knowing the first. In April 2025 the Federal Trade Commission wrote to the operators of websites charging up to $300 per EIN while borrowing the IRS's seals, logos, layout and colours, putting "IRS" in their domain names and displaying "EIN Assistant" — the name of the IRS's own free tool — without clearly saying they weren't the IRS. The FTC warned that this may violate the FTC Act and the Impersonation Rule. The section further down is how to tell them apart in about four seconds.

The IRS requires an EIN when the business has employees, when it operates as a corporation or partnership, when it files employment, excise or alcohol/tobacco/firearms returns, when it withholds tax on income paid to a non-resident alien, or when it has a pension, profit-sharing or retirement plan. Trusts, estates and non-profits generally need one too.

Most small businesses reading this are in a quieter category: not required, but obviously worth it. A sole proprietor with no employees can legally use their Social Security number — and then hands that number to every client who needs a W-9, prints it on invoices, and gives it to a payment processor. An EIN costs nothing and keeps it private. The IRS itself notes that most new single-member LLCs classified as disregarded entities will need one anyway, because banks ask.

A single-member LLC is a special case worth stating clearly: for income tax it's disregarded, so the profit still goes on the owner's return — but for employment tax and certain excise taxes the IRS treats it as a separate entity, which is exactly when it needs its own number. That's why the answer to "does my one-person LLC need an EIN" is usually yes in practice even when it's no in theory.

If you can't use the online form, Form SS-4 works by fax — generally about four business days when you give a return fax number — or by post, which the IRS puts at roughly four weeks. Same form, same number, same price.

One field on the application carries more weight than the rest. The responsible party is the person who owns, controls or exercises effective control over the entity and directly or indirectly manages its funds and assets. For a single-member LLC that's you. For a partnership it's a general partner; for a corporation, a principal officer; for a trust, the grantor or trustee.

It must be a natural person, not a company. The IRS is explicit: the responsible party must be a person, not an entity, with the sole exception of government entities. You cannot list a holding company, a formation service or a registered agent — and the number that goes in the box is that person's SSN or ITIN.

Nominees cannot apply. A nominee is someone given limited authority to act for the entity during its formation with little or no control over its assets — the IRS says nominees can't apply for an EIN and shouldn't be listed on Form SS-4. This is worth knowing if a formation service offers to "handle the EIN": it can act as a third-party designee with your signed authorisation, but it cannot put itself in the responsible-party box, and the number is still free.

When the responsible party changes — you sell, a partner takes over, the controlling officer leaves — file Form 8822-B within 60 days. It's free, it's a single page, and it keeps the IRS writing to the right person, which matters enormously the first time something goes wrong.

The EIN is what opens the next few doors, so use it straight away while the confirmation letter is still on your desk: open a business bank account in the company's name; put the EIN on your Stripe or Square account so payouts and the 1099-K land under the business rather than under you; use it on W-9s instead of your Social Security number; and register with your state's tax department for sales tax or payroll withholding if either applies.

Two things people worry about unnecessarily. It doesn't expire — an EIN is issued once and stays attached to that entity; if you stop needing it the IRS can deactivate the account but never reissues the number to anyone else. And it isn't secret in the way a Social Security number is: it appears on forms you hand out routinely. Treat it as an identifier to be careful with rather than a credential, and keep the CP 575 letter itself somewhere safe, because that's the document that proves the number belongs to your business.

Getting an EIN is also not a tax election. It doesn't make you an LLC, it doesn't change how you're taxed, and it doesn't create any filing obligation you didn't already have. If you want the business taxed differently — as an S-corporation, say — that's a separate election with its own form and its own deadline, and the maths behind whether it's worth it is here.