An EIN costs nothing and takes about fifteen minutes. The reason this guide exists is that search results for it are dominated by companies charging $50 to $300 to fill in a free government form on your behalf — and by the time you notice, you have paid for typing.
What follows is the actual process: whether you need one at all, what the application asks before you start, the three routes in and who is forced onto the slow ones, and the error codes that stop an application dead.
$0
IRS fee, always
~15 min
Online, number issued on screen
1 / day
Limit per responsible party
4–5 wks
If you end up applying by mail
On the details below: application hours, processing times, the daily limit and the error codes were checked against IRS guidance in August 2026. The EIN process is one of the more stable things in this guide series — the form has barely changed in years — but IRS service hours and phone numbers do move. The authoritative page is on irs.gov, and it is the only page you should be entering your details into.
Do You Actually Need One?
An EIN — Employer Identification Number, also called a Federal Tax ID — is a nine-digit number in the format 12-3456789 that identifies a business to the IRS the way an SSN identifies a person. The IRS requires one in a short list of situations. Everyone else gets one for practical reasons.
| Situation | EIN required? |
|---|---|
| You have, or will have, employees | Yes |
| You operate as a corporation or a partnership | Yes |
| Multi-member LLC (taxed as a partnership by default) | Yes |
| You file excise, alcohol, tobacco or firearms returns | Yes |
| You withhold tax on income paid to a non-resident alien | Yes |
| You have a Keogh or a solo 401(k) | Yes |
| Single-member LLC, no employees, no excise tax | No — but get one |
| Sole proprietor, no employees | No — but get one |
The two "no" rows are where most new owners land, and almost all of them apply anyway. Three reasons. Banks: opening a business account without an EIN is possible at a handful of providers and awkward everywhere else. Clients: any company paying you more than $600 in a year wants a W-9, and the alternative to an EIN on that line is your Social Security number, sitting in the accounts payable folder of every client you have ever invoiced. Payroll: the day you hire someone you need one anyway, and the number takes fifteen minutes, so there is nothing to gain by waiting.
One EIN, one business
A separate legal entity needs a separate EIN. Two LLCs, two numbers. But a single LLC running three DBAs is one entity and one EIN — trade names are not entities and cannot hold their own number. If you are unsure which you have, look at what the state approved: a certificate of formation is an entity, a fictitious name registration is not.
Get the Order Right
The EIN is step two, not step one. Register the entity with the state first, wait for approval, then apply. The application asks for the legal name, the state of formation and the formation date, and the IRS issues the number against exactly what you type — it does not check the state register.
Apply as a sole proprietor in March and form an LLC in April and you now have a number attached to a business structure you no longer operate. Nothing breaks immediately. It surfaces later, at the bank, on a payroll enrolment, or on the first return that has to reconcile a name the IRS holds with the name on your operating agreement. The fix is a letter and a wait. Getting the sequence right costs a few days of patience: entity, EIN, business bank account, then everything else in the first 30 days.
If the entity itself is still undecided, that decision comes before this page — LLC vs sole proprietorship covers the trade-off, and the LLC formation guide has the filing fee for each state.
What the Application Asks
The online session times out after about fifteen minutes of inactivity and does not save what you have entered, so have the answers ready before you open it. Everything below comes off Form SS-4, whichever route you use.
- Legal name of the entity — exactly as the state approved it, including "LLC" or "Inc."
- Trade name / DBA, if you operate under a different one
- Mailing address — a PO box is accepted for mail, but you also give a physical street address
- State and country of formation, and the county
- Entity type — sole proprietor, partnership, corporation, LLC (and the number of members)
- Reason for applying — started a new business, hired employees, banking purposes, changed type of organisation
- Date the business started or was acquired
- Closing month of the accounting year — December unless you have a specific reason
- Highest number of employees expected in the next 12 months — zero is a valid answer
- Principal activity and the products or services sold
- Responsible party — full legal name and SSN, ITIN or EIN
The responsible party is the one field to think about
The IRS defines it as the natural person who ultimately owns or controls the entity and directs its funds and assets. Not the lawyer, not the accountant, not the registered agent, and — outside of specific government and trust cases — not another company. On a single-member LLC it is you.
It matters because this is the person the IRS will contact, and the only person who can request a replacement confirmation letter later. If it changes, you file Form 8822-B within 60 days. Put a partner or a service provider here and every future EIN conversation runs through them.
Three Ways In, and Who Is Forced Onto the Slow Ones
| Route | Time to number | Who it is for |
|---|---|---|
| Online (IRS EIN Assistant) | Immediate | Business in the US or a US territory, responsible party has an SSN or ITIN |
| Fax Form SS-4 | ~4 business days | No SSN or ITIN, or the online tool rejected you |
| Mail Form SS-4 | 4–5 weeks | Last resort — no reason to choose it over fax |
| Phone (international line) | During the call | Applicants whose business is outside the US |
Online
The IRS EIN Assistant runs on weekdays, roughly 7am to 10pm Eastern — it is not a 24-hour service, which surprises people applying at midnight from the west coast. You answer the questions above, the last screen shows the number, and you download the CP 575 confirmation letter there and then. Download it. The IRS does not reissue that letter; the replacement is a different document you have to phone for.
One limit that trips up anyone forming several entities at once: the IRS issues one EIN per responsible party per day, across all routes. Three LLCs means three days, or a different responsible party for each — and the responsible party has to be genuine, so inventing one to beat the limit is not an option.
Fax
Download Form SS-4, complete it, and fax it to the number on the form's instructions for your state or for international applicants. Include a return fax number: with one, the IRS faxes the EIN back in about four business days; without one, you are on the mail timeline. This is the standard route for founders without an SSN, and an online fax service is enough — you do not need a machine.
If You Have No SSN or ITIN
This is where the paid services earn their fee, and where most bad advice lives. A non-US founder can hold an EIN, and the entity can be a US LLC owned entirely from abroad. The online tool will not do it, because it validates the responsible party's SSN or ITIN before issuing.
What you do instead: complete Form SS-4, write "Foreign" on the responsible party's tax ID line, and fax or mail it. If the business itself is located outside the US, you can also call the IRS international line on +1-267-941-1099 — not a toll-free number, and staffed on Eastern-time business hours — and be issued the number during the call.
You do not need an ITIN first. This is the single most expensive misconception on the topic. An ITIN is an individual taxpayer number for people with a US filing obligation; getting one takes weeks and often a certified copy of a passport. The EIN application does not require it — "Foreign" on that line is the documented answer. Anyone telling you to obtain an ITIN before you can apply is either mistaken or selling the ITIN service.
If you do use a filing service, note that authorising someone as a third-party designee on the SS-4 lets them receive the EIN on your behalf, and that authority ends once the number is issued. It does not give them any standing afterwards — including the standing to request the replacement letter.
The Error Codes
The online tool fails with a bare reference number and no explanation. The four you are likely to see:
| Reference | What happened | What to do |
|---|---|---|
| 101 | Name conflict — an existing entity looks like a match for your name and state | Not solvable online. File SS-4 by fax or call; a person resolves it |
| 102 | The responsible party's SSN or ITIN did not match IRS records | Check for a typo and retry once, then fax the SS-4 |
| 109 / 110 / 112 | Technical — the system is busy or unavailable | Nothing is wrong with your application. Try again later in the day |
| 114 | The responsible party already received an EIN today | Wait until tomorrow — this is the one-per-day limit |
Reference 101 is the one worth understanding, because the instinct is wrong. Faced with a name conflict, people reapply with a slightly different name — adding "Group", dropping "The" — and get the same error, or worse, succeed and end up with an EIN registered to a name that does not match their formation certificate. The conflict is often an old entity of your own: a sole proprietorship that already has a number under the same responsible party, or an LLC you dissolved and forgot. Fax the SS-4 and let the IRS look at it.
After You Have the Number
- Save the CP 575 in two places. The confirmation letter is issued once and never reissued. Banks, payroll providers and some licensing boards ask for it.
- Open the business bank account. Bring the CP 575 and the state formation documents. This is the step that makes the liability separation real rather than theoretical — see business bank accounts.
- Check your state's separate registration. The EIN is federal. State income tax withholding, unemployment insurance and sales tax permits are separate numbers from separate agencies, and a state ID is not issued alongside the EIN.
- Use it on W-9s instead of your SSN. The main practical payoff for a sole proprietor, and the reason to get one you are not required to have.
- File something. An EIN with no return filed against it eventually looks dormant to the IRS. If the business is running, the annual return is what keeps the record live.
When you need a new EIN — and when you do not
Keep the same number: changing the business name, moving address, opening additional locations, changing what you sell, electing S corporation status on Form 2553, or a single-member LLC adding a DBA. A name change is a letter to the IRS or a box on the return, not a new application.
Apply for a new one: a sole proprietorship incorporating or forming an LLC, a partnership becoming a corporation, a single-member LLC electing to be taxed as a corporation, a new owner taking over an existing business, or a sole proprietorship going through bankruptcy proceedings. The rule underneath all of these is that the entity changed, not the label on it.
One last thing worth knowing: an EIN cannot be cancelled. If the business closes, the IRS closes the business account associated with the number, but the number itself is retired permanently and never reassigned to anyone else. There is no cost to holding one you no longer use, and no way to give it back.
With the number in hand, the next costs are the ones that vary by state — the business license fee and whatever your industry needs on top. If you have not registered the trading name yet, how to register a business name covers that side.