What is an ITIN number?

An ITIN has nine digits in the same layout as a Social Security number, 9XX-XX-XXXX, and it always begins with 9. The IRS describes the fourth and fifth digits as falling in the ranges 50 to 65, 70 to 88, 90 to 92 and 94 to 99.

On a federal return, your ITIN goes in the space for the Social Security number. ITIN is short for Individual Taxpayer Identification Number, so “ITIN number” says number twice; the IRS’s own pages sometimes call it an individual tax identification number.

You need an ITIN if you have a federal tax purpose and cannot get an SSN. The IRS lists the usual cases, and they cover most people who ask.

This is where the misunderstandings live, and the IRS is blunt about them. An ITIN does not authorize you to work legally in the United States. It does not qualify you for Social Security benefits. It does not make you eligible for the Earned Income Tax Credit.

It is also not immigration status, and applying for one does not give you any. Nor does it serve as identification outside the federal tax system. It is a filing number, nothing more.

Filing, mostly, and everything that follows from filing. With an ITIN you can file the return you are required to file, claim a refund you are owed, be claimed on a family member’s return where the rules allow it, and satisfy a withholding agent who needs a taxpayer number under a treaty.

Banks, payment processors and state agencies often ask for a taxpayer number too. What they accept is their own rule, not the IRS’s, so check with them rather than assuming an ITIN opens every door.

The IRS sends your ITIN in an assignment letter, Notice CP565, and that letter is what people mean by an ITIN letter. Check that the name and date of birth on it are right; you do not need to reply to it.

Keep it. You file with the ITIN and the name exactly as the notice shows them, and if you later get a Social Security number, a copy of the notice goes with your letter asking the IRS to combine your records under the SSN. If you mailed original documents, they come back within 60 days of the notice date.

If you have lost it, contact the IRS: 800-829-1040 in the United States, or 267-941-1000 from abroad. Two other notices come from the same process: CP566 means the IRS needs more information, and CP567 means the application was rejected and has to be sent again.

An ITIN expires if it is not used on a U.S. federal tax return for three consecutive tax years. The IRS puts the date at 31 December after the third of those years, and the number has to be renewed before it goes on a return again.

An ITIN assigned before 2013 that was never renewed has already expired and needs a renewal application with your federal return. If your number is only used on information returns, such as a Form 1099, the IRS says you do not need to renew it until you file a return with it. The ITIN renewal guide linked below covers the rest.

One useful exception. The IRS says an ITIN is not needed to request an extension on Form 4868 or to make estimated tax payments on Form 1040-ES or 1040-ES (NR). If money is due before your number arrives, the payment does not have to wait for the number.