What Is an ITIN?
An ITIN is a US tax ID number for people who need to deal with the IRS but can't get a Social Security Number. Here's what it is, how you apply, and — just as importantly — why owning a US company usually doesn't require one on its own.
What it is
ITIN stands for Individual Taxpayer Identification Number. It's a nine-digit number the IRS issues to a person who has a US tax reason to have an identifying number but isn't eligible for a Social Security Number (SSN). It always begins with the digit 9 and is written in the same 9XX-XX-XXXX shape as an SSN. Think of it as the IRS saying: "You're not eligible for an SSN, but we still need a way to identify you on a tax filing, so here's a number for that purpose."
An ITIN does one job: it identifies an individual to the US tax system. It is not a work permit, it isn't immigration status, and it doesn't give you the right to live or work in the US. It exists purely so the IRS can process a filing tied to a specific person who has no SSN.
ITIN vs EIN — a common mix-up
This trips up almost every foreign founder, so it's worth being crisp. An ITIN is for a person. An EIN is for a company. They are different numbers for different taxpayers, and needing one tells you nothing about needing the other. Your US LLC gets an EIN; you, the human being who owns it, might — or might not — ever need an ITIN. If the whole family of nine-digit numbers is blurry, our guide to EIN vs ITIN vs SSN lines all three up side by side. The short version: the company's tax ID is the EIN, and the ITIN only enters the picture when you personally have a US tax obligation.
When you actually need an ITIN
Here's the reassuring part for most non-resident business owners: simply owning a US LLC and getting it an EIN does not require you to have an ITIN. When you apply for the company's EIN on Form SS-4, a foreign owner with no SSN or ITIN just writes "Foreign" in the field asking for a personal tax number — so the company is set up without you needing an ITIN at all. You typically need an ITIN only when you as an individual have to interact with the US tax system directly, such as:
- You have to file a personal US tax return. For example, you have US-source income that requires you to file a non-resident individual return (Form 1040-NR), and you need a number to put on it.
- You're claiming a tax-treaty benefit or a reduced rate of withholding, and the form requires a US taxpayer number to identify you.
- Someone is required to report payments to you or withhold US tax on money paid to you, and they need your taxpayer number to do it.
- Your business is taxed in a way that flows income to you personally — for instance, a multi-member structure that reports each owner's share — creating a personal filing requirement.
If none of those apply — the common case for a non-resident who owns a single-member LLC that the IRS disregards — you can often run the company for a long time without ever needing an ITIN. The company still files its own annual Form 5472, but that's the company's filing under its EIN, not yours.
How you apply: Form W-7
You request an ITIN with IRS Form W-7. The important thing to understand is that, as a general rule, you don't file the W-7 on its own — you attach it to the US tax return that creates the need for the number, and the two are processed together. In other words, the ITIN usually comes into existence because you have a return to file, not before. There are specific exceptions where a W-7 can be filed without a return (certain treaty and third-party-reporting situations), but the default path is "W-7 plus the return that requires it."
You also have to prove who you are. The IRS requires original identity documents — most commonly a passport — or copies certified by the issuing agency. Because mailing your only passport to the IRS is nobody's idea of a good time, the system provides Certifying Acceptance Agents (CAAs): authorized people and firms who can verify your passport in person or remotely and send the IRS the certification instead, so your document stays with you. Using an acceptance agent is the usual way non-residents handle the identity step without parting with their passport.
Good to know
A couple of practical points. ITINs can expire: if you don't use your ITIN on a US federal return for three years in a row, it lapses and has to be renewed before it can be used again. And processing takes time — an ITIN application is a paper, hand-reviewed process, so it's best started well ahead of any deadline that depends on it, in the same way the EIN-without-an-SSN route needs lead time.
What we handle for you
We first tell you honestly whether you even need an ITIN — many owners are relieved to learn they don't yet — and, when you do, we prepare the Form W-7 correctly, coordinate the identity certification so you keep your passport, and file it alongside the return that requires it. It's part of our US market-entry service, where your company's EIN and your personal tax numbers are handled in the right order rather than guessed at. Tell us your situation and we'll sort out which numbers you actually need.