Get an ITIN if you cannot get an SSN

An Individual Taxpayer Identification Number (ITIN) is a nine-digit number issued by the IRS to people who have a U.S. tax obligation but cannot get a Social Security number. It always begins with 9.

An ITIN is only a tax number. It does not authorise work, does not affect immigration status, and does not entitle you to Social Security benefits or the Earned Income Tax Credit.

Cost

Free from the IRS

Form

W-7, filed with your tax return

Time

7 weeks, 9–11 weeks in filing season

Expires

After three years of not being used on a return

Who needs one

• A non-resident who must file a U.S. tax return
• A spouse or dependent being claimed on someone else's return who has no SSN
• Someone earning U.S. income who is not authorised to work

Note the order of precedence: if you are eligible for a Social Security number, you cannot have an ITIN, and applying for one anyway will be refused. Apply for the SSN first — see applying for a Social Security number.

How to apply

Form W-7 is normally filed together with your tax return, not separately, and requires proof of identity and foreign status. That coupling surprises people: the return that cannot be filed without the number is the same envelope that requests the number.

The three routes are:

1. By post with your original passport. The IRS returns it, but you may be without it for weeks — usually the worst option, and unusable if you need to travel or prove status in the meantime.
2. Through a Certifying Acceptance Agent (CAA). A CAA verifies your passport and returns it to you immediately, sending certified copies instead. They charge a fee. For most people this is the practical choice.
3. At an IRS Taxpayer Assistance Center, by appointment. Free, and your documents are checked and returned on the spot. Appointments are limited and book out well before April.

Dependants need documents too

Claiming a spouse or child on your return means an ITIN for each of them, each with its own W-7 and its own proof of identity and foreign status. For children this usually means a passport, or a birth certificate together with a document showing U.S. residency — medical or school records are commonly accepted. Assembling these is the slow part; start before you start the return.

Renewal

An ITIN that is not used on a federal tax return for three consecutive years expires. An expired ITIN does not stop you filing, but it delays the return and any refund, and credits claimed on the return may be disallowed until it is renewed.

Renew before filing season rather than during it. Renewal uses the same Form W-7, marked as a renewal, and does not require a tax return to be attached.

If you later get an SSN

Once you receive a Social Security number, stop using the ITIN immediately and notify the IRS so that they combine the records. This is not administrative tidiness: until it is done, tax paid and income reported under the ITIN sits apart from your SSN, which can reduce a refund and leaves your earnings history incomplete.

The IRS voids the ITIN and reassigns the prior tax information to the SSN. Keep the confirmation.