ITIN numbers start with the digit 9. Every Individual Taxpayer Identification Number issued by the IRS is a nine-digit number in the format 9XX-XX-XXXX, and that leading 9 is the quickest way to tell an ITIN apart from a Social Security Number.1Internal Revenue Service. Individual Taxpayer Identification Number (ITIN)
The Full Nine-Digit Format
An ITIN uses the same NNN-NN-NNNN layout as a Social Security Number so it fits cleanly into tax forms and software.2Internal Revenue Service. Taxpayer Identification Numbers (TIN) The identifying details are in the digits themselves. The first digit is always 9. The fourth and fifth digits (the first two of the middle pair) fall inside IRS-designated ranges:3Internal Revenue Service. IRS Individual Taxpayer Identification Number (ITIN) Real-Time System
- 50 through 65
- 70 through 88
- 90 through 92
- 94 through 99
The numbers 89 and 93 are reserved for other IRS programs and never sit in that middle position on an ITIN.3Internal Revenue Service. IRS Individual Taxpayer Identification Number (ITIN) Real-Time System The general nine-digit structure and the IRS’s authority to designate specific numbers within it come from 26 C.F.R. § 301.6109-1.4GovInfo. 26 CFR 301.6109-1 – Identifying Numbers
So the recognition test is simple. If a nine-digit tax ID begins with 9 and the fourth and fifth digits fall in one of those four ranges, it’s an ITIN. If the first digit is anything else, or the middle pair sits outside those ranges, it isn’t.
Telling an ITIN From a Social Security Number
On paper the two look almost identical. Same nine digits, same hyphen pattern, same field length in databases. The differences are:
- An SSN never starts with 9. An ITIN always does.
- An SSN’s middle two digits can be anything from 01 to 99 (with some carve-outs). An ITIN’s fourth and fifth digits are restricted to the ranges above.
That’s it visually. The practical difference between the two numbers has nothing to do with what they look like and everything to do with what they authorize.
What the Number Does and Doesn’t Authorize
Because the format mirrors an SSN so closely, people often assume the two do the same work. They don’t. The IRS is specific: an ITIN does not qualify you for Social Security benefits, does not authorize you to work in the United States, does not change your immigration status, and is not valid identification outside the federal tax system.1Internal Revenue Service. Individual Taxpayer Identification Number (ITIN)
Its only job is federal tax reporting. The IRS issues ITINs to people who need a taxpayer identification number but don’t qualify for an SSN, including nonresident aliens, resident aliens, and their spouses or dependents.1Internal Revenue Service. Individual Taxpayer Identification Number (ITIN) Presenting one as proof of work authorization is not permitted, and it confers no employment status on the person holding it.
Credit Rules Tied to Which Number You Have
Two federal tax credits depend on whether you’re filing with an SSN or an ITIN, and the distinction catches filers off guard.
The Earned Income Tax Credit is unavailable to anyone filing with an ITIN. If you (or your spouse on a joint return) use an ITIN instead of an SSN, you can’t claim it. Every qualifying child listed for the EITC must also have a valid SSN.5Internal Revenue Service. Basic Qualifications
The Child Tax Credit follows a similar rule. A child claimed for the Child Tax Credit or the Additional Child Tax Credit must have an SSN. A child listed with an ITIN cannot be claimed for either credit, even when the child is a U.S. citizen or resident and meets every other test.6Internal Revenue Service. Child Tax Credit 4 Citizenship alone isn’t enough; the specific identifier on the return is what the IRS checks.
When an ITIN Stops Working
The number itself doesn’t change format over time, but it can go inactive. If an ITIN isn’t used on a U.S. federal tax return for three consecutive tax years, it expires on December 31 of that third year.7Internal Revenue Service. How to Renew an ITIN Older ITINs assigned before 2013 and never renewed also need renewal before they can appear on a return again.
An expired ITIN still looks like an ITIN, because the digits don’t change. What changes is whether the IRS will accept it on a return. Filing with an expired number can delay processing and block certain credits until renewal goes through, which may translate into a reduced refund or into penalties and interest.7Internal Revenue Service. How to Renew an ITIN One useful boundary: an expired ITIN can still appear on information returns like a Form 1099. Renewal is only required when the number will be on a tax return you’re actually filing.
Quick Recognition Checklist
If you’re trying to identify a nine-digit number in front of you, run through these in order:
- Does it start with 9? If not, it isn’t an ITIN.
- Are the fourth and fifth digits between 50–65, 70–88, 90–92, or 94–99? If yes, the format matches.
- Are those two digits 89 or 93? Then it isn’t an ITIN, because those values are used elsewhere at the IRS.
The number that passes all three checks is an ITIN in format. What it entitles the holder to, and what it doesn’t, is a separate question governed by the tax rules above rather than by the digits on the card or notice.