ITIN vs EIN vs SSN: which tax ID a foreign founder actually needs

Three numbers, three different jobs

All three are nine digits. All three get called “a tax ID” by somebody trying to sell you one. That is where the resemblance ends: they are issued by two different agencies, they belong to two different legal persons — you, and your company — and each one opens different doors.

Keep the files separate and most of the confusion in this market evaporates. An EIN never stands in for a personal number, an ITIN never identifies a company, and no one of the three is a shortcut to another.

The SSN: who has one, and why founding a company does not get you one

The Form W-7 instructions state the eligibility plainly: you are eligible for an SSN if you are a US citizen, or if you have been admitted by the United States for permanent residence or for US employment. Owning an American LLC is none of those things. Formation confers no immigration status, no work authorization, and no path to a Social Security number — and any service implying otherwise is selling fiction.

Two consequences follow. First, every legitimate workflow for a foreign founder is built on the assumption that you do not have an SSN; that is the normal case, not an exception. Second, if your circumstances change and you later become eligible for an SSN, you use the SSN from then on — the IRS does not issue an ITIN to someone who holds an SSN, and an ITIN you already have stops being used.

The EIN: your company’s number, and why no SSN or ITIN is required to get one

The EIN is the one number on this page your company cannot operate without — and the one that asks nothing personal of you. The IRS issues it free; its own application page warns, “Beware of websites that charge for an EIN. You never have to pay a fee for an EIN.” What services like ours charge for is the paperwork handling around it, never the number.

The online application is the part that misleads people. It requires the responsible party to enter an SSN or ITIN and is built for applicants with a US presence, so for a founder abroad it stops at the first screen. The documented route for international applicants is Form SS-4, submitted by fax or mail — or by phone on the IRS international line, 267-941-1099. On the line asking for the responsible party’s SSN or ITIN, a founder who has neither and is not eligible for one writes “Foreign” — the IRS-accepted entry, not a fudge. A third-party designee named on the form can receive the number and answer the IRS’s questions about the application, which is how a formation handler tracks it for you.

On timing, hold both facts at once: the SS-4 instructions describe faxed applications as generally answered within four business days, while Sethhost publishes a typically 15–25 business-day expectation, because volume stretches the fax queue and a returned confirmation can fail. We would rather the IRS beat our estimate than the reverse. One more IRS rule explains why “instant EIN” promises collapse: issuances are limited to one EIN per responsible party per day, across every channel.

The full fax workflow — numbers, order of steps, the lost-confirmation route — is walked through in Guide 01, EIN without an SSN. The service itself is on the EIN application page.

The ITIN: a personal number for specific tax situations

An ITIN exists for one reason: someone who is not eligible for an SSN still has business with the US tax system as an individual. The IRS issues it on Form W-7, and the application generally travels with a US federal tax return unless a specific exception applies — you do not apply for one speculatively, “just in case.”

The IRS’s ITIN page is equally plain about what the number is not. An ITIN does not authorize you to work legally in the US. It does not provide or change immigration status. It does not qualify you for Social Security benefits or the Earned Income Tax Credit, and it does not serve as identification outside the federal tax system. Topic No. 857 adds the sentence that matters most to founders: an ITIN does not get issued solely for opening bank or investment accounts, e-commerce, or starting a business.

ITINs also expire. One that has not been used on a federal tax return at least once in three consecutive tax years expires on December 31 of the third year, and is renewed on Form W-7 when a filing purpose returns. If yours is only being used on information returns filed by third parties, the W-7 instructions say you do not need to renew it until you next file a return of your own.

The five situations where a foreign founder genuinely needs an ITIN

These come from the eligibility categories in the Form W-7 instructions, translated into founder situations. If none of them is you, you almost certainly do not need an ITIN today.

• You personally owe a US individual return. Income in your own name that must be reported on Form 1040-NR — or a refund you are claiming — makes the W-7 necessary; it is filed attached to the front of that return.
• Your LLC has a second member. A multi-member LLC is taxed as a partnership: it files Form 1065 and issues a Schedule K-1 to each member, and each foreign member needs a personal taxpayer number for that reporting and for any §1446 withholding on their share.
• You claim a treaty benefit that requires one. The W-7 instructions name the case directly: a nonresident alien claiming reduced withholding under an income tax treaty for which an ITIN is required.
• A family filing puts you on a US return. Electing to file jointly with a spouse who is a US citizen or resident, or being claimed for an allowable tax benefit on someone’s return, both run through a W-7.
• A named W-7 exception fits your facts. The instructions’ exception tables cover certain third-party withholding and reporting situations — US-source income reported to you personally, a disposition of a US real property interest among them — where documents substitute for an attached return. The exception has to be identified by name before filing; this is preparer territory, not a guess.

The situations where sellers claim you need an ITIN — and you do not

• Forming the LLC. No personal US number of any kind is a formation prerequisite, in any state Sethhost files in.
• Getting the EIN. The SS-4 route above exists precisely for owners with neither an SSN nor an ITIN. Being told to “get an ITIN first” adds weeks and an original-passport mailing to a process that never required it.
• Filing Form 5472. It is the company’s annual filing, made under the company’s EIN — our Form 5472 guide covers who files and what counts. No ITIN is a prerequisite.
• Opening the bank account or the Stripe account. The IRS does not issue ITINs for this purpose (Topic No. 857). Providers verify the company’s document set — formation record, EIN letter, operating agreement, owners’ passports — which is the subject of our guide to US banking and Stripe for foreign founders.
• Filing an extension or an estimated payment. The W-7 instructions route this explicitly: write “ITIN TO BE REQUESTED” where the number belongs on Form 4868 or the payment voucher, and do not file a W-7 with it.

There is also a cost to an unnecessary W-7 beyond the fee someone charges you: the application asks for original identity documents, or certified copies from the issuing agency. Mailing your passport to support a number you do not need is risk taken for nothing.

How the three interact inside the Sethhost bundle

The EIN workflow is handled inside Hosted: the SS-4 is prepared from your intake facts, you confirm the responsible-party details before submission, and the application is tracked until the assignment letter arrives and is mirrored into your portal. The SSN never enters the picture — nothing in the bundle needs one, and nothing in it can produce one.

The ITIN is deliberately outside the bundle. Sethhost does not prepare Form W-7 and does not sell ITIN filing, because the five genuine cases above are tax situations, and they belong to a tax preparer. When one of them is genuinely yours, we will say so plainly and point you to the two routes the IRS itself documents: a qualified CPA, or an IRS Certified Acceptance Agent (CAA), who can certify your identity documents so the originals do not travel by mail. What we will not do is bundle an ITIN into a formation package as if it were a formation step.

What to read next

Start with EIN without an SSN for the fax workflow itself, then Form 5472, explained before it costs you $25,000 for the annual filing the EIN leads to. When you are ready to see the whole engagement priced in one place, the pricing ledger itemizes Hosted, with formation included in the first term and the state fee shown separately, as always.

Verified November 5, 2026 against: IRS, “Individual Taxpayer Identification Number (ITIN)” and Topic No. 857 (irs.gov); Instructions for Form W-7 (Rev. December 2024); IRS, “Get an employer identification number” and Instructions for Form SS-4 (Rev. December 2025). Sethhost is not a tax firm; whether an ITIN is required in your case is a question for a tax preparer.