Getting an EIN (also called an EIN number) is one of the first pieces of paperwork every new business needs, and the good news is it's free and usually fast. The IRS gives you three ways to apply: online, by fax, or by mail, plus a phone option if your business has no legal residence, principal place of business, or principal office in the US. Online is fastest (you can walk away with your EIN the same session), but it comes with eligibility limits that fax and mail don't have.
This guide walks through what you need before you apply, how each application method works, current IRS processing times, and what happens if the person applying doesn't have a Social Security number.
Fastest option: Apply online through the IRS EIN Assistant and you can receive your EIN immediately, but only if your business is US-based and the responsible party has a valid SSN or ITIN.
What you need first: Form your business entity with the state before you apply. The IRS wants a legally formed LLC, corporation, or partnership on file, not a plan to form one.
No SSN or ITIN? You can still get an EIN, but you'll need to apply by fax or mail (or by phone if you're an international applicant), which takes longer than the online path.
How do you get an EIN?
Form your LLC or corporation with the state first, then file Form SS-4 with the IRS for free. Per the IRS, an online application issues the EIN immediately once approved if your business is US-based and the responsible party has an SSN or ITIN; otherwise you apply by fax (about 4 business days), by mail (about 4 weeks), or by phone if your business has no US presence.
Best for founders forming a Delaware C-corp who want their company formed and a business account opened in the same flow, subject to approval: Rho. When you incorporate a Delaware C-corp with Rho, your EIN application is filed for you. We assess formation options on price, what's included, and whether a business account can open in the same flow as formation.
What is an EIN and why you need one
An EIN, or Employer Identification Number, is the nine-digit number the IRS assigns to identify your business for tax purposes. It's what a bank, a state tax agency, or a payroll provider uses to recognize your business the way a Social Security number identifies an individual. You'll need one to open a business bank account, hire employees, file certain tax returns, and apply for most business credit products. Once you have your EIN, review the documents you need to open a business bank account.
If you're trying to confirm a number you already have rather than apply for a new one, see how to look up an EIN you already have. And if the terminology needs sorting out first, here's how an EIN differs from a TIN.
What you need before you apply
The IRS won't issue an EIN to a business that doesn't legally exist yet. Before you start the application, have these ready:
Your business already formed with the state. Form your business entity first, then apply for the EIN. The IRS says that if you don't form your entity with the state first, your EIN application may be delayed.
A responsible party. This is the person who ultimately owns or controls the business and who the IRS will associate with the EIN. They need a valid SSN or ITIN to apply online; see the section below if they don't have one.
Your entity type. Sole proprietorship, single-member LLC, multi-member LLC, corporation, partnership, and so on. The SS-4 form asks you to specify this, and picking the wrong one is a common source of delay.
A mailing address and the legal business name, exactly as it's registered with the state. A mismatch here is another frequent cause of rejected applications.
Only one EIN is issued per responsible party per day, across all application methods, so plan accordingly if you're forming more than one entity.
How to apply for an EIN: the 3 ways to file Form SS-4
Every EIN application, regardless of channel, is the same underlying form: IRS Form SS-4. The channel you use just determines how fast you get an answer.
Apply online (IRS EIN Assistant)
This is the fastest method and the one most US-based businesses should use. The online assistant is available Monday through Friday, 6:00 a.m. to 1:00 a.m. Eastern time (the next day), Saturday 6:00 a.m. to 9:00 p.m., and Sunday 6:00 p.m. to midnight. If you're approved, your EIN is issued immediately and you can print your confirmation letter on the spot.
Two catches: your session can't be saved partway through, and it expires after 15 minutes of inactivity, so have all your information ready before you start. You're only eligible to use this method if your principal place of business is in the US or a US territory, and if the responsible party has a valid SSN or ITIN.
Apply by fax
If you're not eligible for the online tool, you can fax a completed SS-4 to the IRS. If your business is located in a US state or DC, fax it to 855-641-6935; this is the route for a domestic applicant whose responsible party has no SSN or ITIN. If your business has no legal residence, principal place of business, or principal office in a US state or DC, fax it to 855-215-1627 (from within the US) or 304-707-9471 (from outside the US).
Apply by mail
Mail is the slowest option, and mostly makes sense if fax isn't practical for you. Send the completed SS-4 to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. Applicants with no legal residence, principal place of business, or principal office in the US use the same city with "Attn: EIN International Operation" instead.
Apply by phone (international applicants only)
If your business has no US legal residence or principal place of business, you can apply by calling 267-941-1099, Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern time. This isn't a general workaround for domestic applicants without an SSN. It's specifically for businesses without a US presence at all.
Processing times by method
Method | Who can use it | Typical processing time | Notes |
|---|---|---|---|
Online | US-based business whose responsible party has a valid SSN or ITIN | Immediate | Fastest option; session expires after 15 minutes idle |
Fax | Anyone, including responsible parties without an SSN or ITIN | About 4 business days | Include a return fax number so the IRS can fax the EIN back |
Anyone | About 4 weeks | Slowest option; IRS notes high volume can add further delay | |
Phone | International applicants (no US presence) only | EIN assigned during the call | 267-941-1099, Monday through Friday, 6 a.m. to 11 p.m. ET |
These are IRS-published figures as of October 17, 2026, not guarantees. Mail volume in particular can push processing past the stated timeframe.
If you don't have an SSN or ITIN
A responsible party without a US Social Security number or ITIN can still get an EIN, just not through the online assistant. On line 7b of the SS-4, enter "Foreign" or "N/A" in the field asking for the responsible party's SSN or ITIN, then apply by fax or mail (or by phone if your business has no US presence at all, as described above).
Expect it to take longer than the online path, since the application moves through a slower channel.
Common mistakes that delay an EIN application
A few errors account for many rejected or delayed SS-4 filings:
Applying before the entity is formed. The state filing needs to be done first.
Choosing the wrong entity type on the form. Single-member LLC and multi-member LLC, for instance, are treated differently.
A business name or address that doesn't match your state filing exactly. Even small discrepancies can trigger a manual review.
Trying to use the online assistant outside its posted hours, or letting the session time out mid-application.
Double-checking these before you submit will save you a resubmission and, if you're on the fax or mail track, another wait.
What to do once you have your EIN
Once your EIN is issued, most of what comes next moves quickly: per the IRS, you can use it right away to open a bank account, apply for business licenses, and file a tax return by mail. A few sibling pieces cover those next steps in more depth, including how to open a business bank account before your EIN arrives and how to get a business credit card with just an EIN.
Where Rho fits
When you incorporate a Delaware C-corp with Rho for $400, your SS-4 (EIN application) is prepared and submitted for you as part of that same flow, and your Rho business account can open in the same flow before the EIN arrives, subject to approval. Funds can move once the EIN is issued and attached to the account. To be eligible for the Delaware C-corp flow, your company needs at least one US-based owner or officer, a physical US operating address, and a business in a non-excluded industry, and founders from restricted countries aren't eligible. Rho also forms LLCs for $349 all in, state filing fee included.
Best for: founders forming a Delaware C-corp who want their company formed and a business account opened in the same flow, subject to approval.
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FAQs
No, not in the sense of having a finished application accepted. The IRS expects your entity to already be legally formed with the state before you apply. Applying earlier risks delay or rejection.
Yes. Applying for an EIN doesn't require a lawyer, an accountant, or a paid formation service. Anyone can complete Form SS-4 directly with the IRS, whether through the online assistant, by fax, by mail, or by phone for international applicants. The one step you can't skip is having your entity legally formed with the state first.
Sometimes, for federal tax filing purposes, if the LLC has no employees. In practice, most banks require an EIN to open a business account regardless, so most single-member LLC owners get one anyway.
Yes, if you're eligible. US-based applicants with a valid SSN or ITIN who apply through the IRS EIN Assistant during its posted hours receive their EIN immediately upon approval.
Yes. The IRS issues EINs at no cost, and you never have to pay a fee to get one directly from the IRS. Anyone can complete Form SS-4 themselves, online if eligible, or by fax, by mail, or by phone for international applicants.
They can still apply, just not through the online assistant. Enter "Foreign" or "N/A" on line 7b of Form SS-4 and apply by fax or mail, or by phone if the business has no US presence. Expect it to take longer than the online path.