What an ITIN is for
An ITIN is a tax processing number for people who have a US tax reporting requirement but are not eligible for a Social Security Number. It exists so that tax can be reported and refunds claimed. It is not work authorisation, it is not identification for non-tax purposes, and it has no bearing on immigration status.
Typical reasons a non-resident needs one: filing Form 1040-NR, claiming a reduced treaty rate on US-source income, being a partner in a US partnership, disposing of US real property, or being claimed as a dependent or spouse on a US return.
The documentation problem
This is where most applications fail. The IRS requires original documents, or copies certified by the issuing agency. A notary's stamp is not enough. For most applicants that means one of two options:
- Mail your actual passport to the IRS and wait for its return. Legally fine, practically alarming, and the reason many people abandon the process.
- Use a Certifying Acceptance Agent (CAA). A CAA verifies your original documents and certifies them, so the passport stays with you.
A valid passport is the only standalone document — it proves both identity and foreign status on its own. Without one you need two documents from the IRS's list, and dependants face additional requirements. Sorting this out before you apply saves months.
The return requirement, and its exceptions
As a rule, Form W-7 is filed attached to the tax return that creates the need for it — you do not apply for an ITIN in the abstract and use it later.
There are defined exceptions where no return is attached, including certain treaty-benefit claims on third-party withholding, some partnership interests, mortgage interest reporting, and dispositions of US real property. Each exception has its own supporting-document list, and claiming the wrong one is a common cause of rejection. We identify which applies before anything is submitted.
Renewals and expiry
An ITIN that is not used on a federal return for three consecutive years expires. Certain older ITINs were also retired in scheduled batches.
An expired ITIN does not stop you filing, but it delays processing and can suspend credits until the renewal is accepted — typically noticed when a refund does not arrive. If you have not filed in a few years, assume renewal is needed and let us check before the filing season.
What we need from you
- Your passport — original, or certified by the issuing authority, or presented to a CAA
- Your foreign address and, where relevant, your US address
- The reason you need the ITIN, and any treaty article you are relying on
- The tax return the W-7 will accompany, or the documents supporting an exception
- Any previous ITIN or IRS correspondence, including prior rejections
- For dependants: proof of residency and relationship
Key facts at a glance
Frequently asked questions
Does an ITIN let me work in the United States?
No. It exists purely for tax reporting. It grants no work authorisation, no immigration status, and no eligibility for Social Security benefits.
Do I have to mail my real passport to the IRS?
Not if you use a Certifying Acceptance Agent, who verifies and certifies your original documents so your passport stays with you. Notarised copies are not accepted by the IRS.
How long does it take?
Plan on roughly seven to eleven weeks once a complete application is received, and longer between January and April. Incomplete documentation is the main cause of delay.
Can I apply without filing a tax return?
Only under one of the defined exceptions, such as certain treaty-benefit claims or dispositions of US real property. Each has its own document list, and claiming the wrong exception gets the application rejected.
My ITIN is old. Is it still valid?
If it has not appeared on a federal return for three consecutive years it has expired. Renewal is straightforward, but it is much better done before filing season than during it.
Not sure which documents you need?
Tell us why you need the ITIN and what identification you hold. We will confirm whether an exception applies and how to get it accepted the first time.
We reply within one business day. Getting in touch is not a client engagement until we confirm it in writing.