An ITIN number is a nine-digit U.S. taxpayer identification number, formatted like an SSN (XXX-XX-XXXX) but always starting with a 9, issued by the IRS to people who need to file taxes but don't qualify for a Social Security Number.
This page is the central reference for the term "ITIN number" — if you're looking for the actual step-by-step application, go to how to apply for an ITIN.
ITIN number vs. SSN vs. EIN
All three are nine-digit U.S. ID numbers, but they serve different purposes. An SSN is for people authorized to work in the U.S. An ITIN is strictly for tax filing by people who aren't SSN-eligible. An EIN identifies a business, not a person. You can't choose between them — your situation determines which one applies to you.
How to read your ITIN number format
Every ITIN follows the pattern 9XX-7X-XXXX or 9XX-8X-XXXX (the middle two digits fall in specific IRS-assigned ranges), which is how a payroll or finance system can distinguish an ITIN from an SSN at a glance.
How to get your ITIN number
Complete Form W-7, attach your supporting identity documents and tax return, and submit by mail, at a Taxpayer Assistance Center, or through a Certifying Acceptance Agent. Processing takes about seven weeks once the IRS has a complete application.
