An ITIN is one of the most searched and most misunderstood numbers in US tax. People hear it mentioned by banks, accountants and online sellers and are unsure whether they need one, what it does and whether it is the same as a Social Security number or an EIN. This guide answers those questions in plain language and walks through how a person living outside the United States can apply.
It is general information, not tax or legal advice. The IRS updates its forms and procedures, so always check the current instructions for Form W-7 before you send anything.
What is an ITIN number?
ITIN stands for Individual Taxpayer Identification Number. It is a nine-digit number the IRS issues to individuals who must file a US tax return or appear on one but are not eligible for a Social Security number (SSN). It always begins with the digit 9 and is written in the same pattern as an SSN, for example 9XX-XX-XXXX.
The ITIN exists purely for tax administration. It lets the IRS match tax filings, payments and withholding to the right person when no SSN is available. It is not a form of identification, a visa, a work permit or proof of any immigration status.
What an ITIN can and cannot do
| An ITIN can | An ITIN cannot |
|---|---|
| Identify you on a federal income tax return | Give you the right to work in the United States |
| Be used to claim certain tax treaty benefits | Qualify you for Social Security benefits |
| Identify a spouse or dependent on a return | Replace a visa or any immigration document |
| Help satisfy requests from banks and tax preparers for a US taxpayer number | Act as the number for a company (that is an EIN) |
Some benefits that depend on a valid work-eligible number are not available to ITIN holders. Always read the rules for the specific credit or benefit rather than assuming an ITIN qualifies.
Who needs an ITIN?
You may need an ITIN if you have a US tax filing or reporting requirement and you cannot get an SSN. Common examples include:
- Non-resident individuals who must file a US return, for instance because of US-source income that is not fully covered by withholding.
- Non-resident owners of US businesses in certain situations where a personal return is required.
- Foreign investors in US property who need to file or claim a treaty position.
- Spouses and dependents of US taxpayers or visa holders who are included on a US return.
- People claiming a tax treaty benefit that requires a taxpayer number on the form.
Equally important, many people who think they need an ITIN do not. Owning a US LLC does not by itself require you to have an ITIN. The company is identified by its EIN, and a foreign owner can usually get an EIN without any personal number. Our guide on ITIN versus EIN explains the difference, and how to get an EIN without an SSN covers the company side.
Do I need an ITIN to open a US LLC or a business bank account?
No, in most cases. Forming an LLC does not require an ITIN, and the EIN is what a US business bank account, payment processor or marketplace usually asks for. A passport and proof of address are the standard documents for a foreign owner. An ITIN becomes relevant only when you personally have to file a US return or claim a treaty benefit.
Because getting an ITIN takes weeks and normally needs a tax return or a qualifying exception, applying for one you do not need wastes time. Confirm the requirement first with a tax professional or with us.
Step by step: how to get an ITIN
Step 1: Confirm the reason
Form W-7 asks you to tick the reason you are applying. Each reason has its own supporting evidence. The most common are: a non-resident alien required to get an ITIN to file a US tax return, a non-resident claiming a tax treaty benefit, a dependent or spouse of a US citizen or resident, and a dependent or spouse of a non-resident alien visa holder. Choose the one that matches your facts, because a wrong box is a common cause of delay.
Step 2: Gather identity and foreign status documents
The IRS accepts a specific list of documents. A valid passport is the only single document that can prove both identity and foreign status by itself. If you do not have a passport, you need at least two other documents from the accepted list, such as a national identity card, a driver's licence, a civil birth certificate, a foreign voter registration card or a foreign military identification card, and they must show your name, photo where applicable, an expiry date that has not passed and your country.
The IRS requires originals or copies certified by the agency that issued them. Ordinary photocopies and notarised copies are not accepted. This is why many applicants use a Certified Acceptance Agent, described below.
Step 3: Complete Form W-7
Form W-7 is short but unforgiving. Enter your name exactly as it appears on your passport, your foreign mailing address, your date and place of birth, your country of citizenship and your foreign tax identification number if your country issues one. Sign and date it. Mistakes in names, dates or the reason box are the most frequent reasons applications come back.
Step 4: Attach a federal tax return or an exception
In most cases the W-7 must be filed together with the tax return that requires the ITIN. The return must be complete and signed. There are limited exceptions where you can apply without a return, for example certain treaty benefit situations, mortgage interest reported by a lender, and third-party withholding on scholarships or partnership income. Each exception needs documentary proof. If you are unsure whether an exception fits, ask before you submit.
Step 5: Choose how to submit
- Mail everything to the IRS. You send the W-7, the return and your original documents. The IRS returns the documents afterwards. Many applicants dislike posting an original passport internationally.
- Use a Certified Acceptance Agent (CAA). A CAA is authorised by the IRS to verify your identity documents and certify copies, so you usually do not have to mail your original passport. The CAA reviews your package and sends it in.
- Visit an IRS Taxpayer Assistance Center by appointment if you are in the United States.
Step 6: Wait for the IRS letter
The IRS sends a letter, called a CP565 notice, with your ITIN, or a letter explaining what was missing. Processing normally takes 8 to 12 weeks. Fast-track processing, which we provide at the same price, usually takes 5 to 6 weeks. Either can take longer than usual during peak filing season and for overseas applications, so allow extra time. Keep the letter safe because it is your proof of the number.
How long does an ITIN last?
An ITIN does not last forever. It expires if it is not used on a federal tax return at least once in three consecutive tax years. Some older ITINs, based on certain middle digits, were expired by the IRS in scheduled waves and need renewal. If yours has expired, the number can be renewed with a new Form W-7. We explain the process in our ITIN renewal guide.
Common mistakes that delay an ITIN
- Applying when only an EIN was needed.
- Choosing the wrong reason box on the W-7.
- Sending plain photocopies instead of certified copies.
- Names that differ between the W-7, the passport and the tax return.
- Leaving out the tax return, or attaching an unsigned one, without a valid exception.
- An unreadable passport scan or an expired document.
- Not responding to an IRS request for more information within the deadline.
ITIN versus SSN versus EIN in one table
| SSN | ITIN | EIN | |
|---|---|---|---|
| Issued to | Eligible individuals (citizens, some residents) | Individuals who cannot get an SSN | Businesses and other entities |
| Issued by | Social Security Administration | IRS | IRS |
| Format | XXX-XX-XXXX | 9XX-XX-XXXX | XX-XXXXXXX |
| Allows work | Yes, where eligible | No | Not applicable |
| Typical use | Personal tax, employment | Personal tax filing without an SSN | Company tax filings, banking, hiring |
How we can help
Our ITIN service prepares your Form W-7, reviews your documents and works with an IRS Certified Acceptance Agent so you do not have to mail your passport. If your real need is a company number, our EIN service is usually faster and cheaper, and our team can tell you honestly which one you need. You can also combine it with US LLC formation and IRS and state tax filing.
Conclusion
An ITIN is a tax processing number, not an identity or immigration document, and many people who hear about it actually need an EIN instead. If you do need one, the process is simple but exact: the right reason, the right documents, a signed return or a valid exception and a careful form. Contact our team if you want us to check your situation before you apply.
