What is an ITIN?
Learn what an ITIN is used for, who may need one, how it differs from an SSN, and why it does not provide work authorization or change immigration status.
Last updated: October 9, 2026
Direct answer
An Individual Taxpayer Identification Number (ITIN) is a nine-digit IRS number for a person who needs a federal taxpayer ID but is not eligible for an SSN. It is for federal tax purposes only; it does not authorize work, provide Social Security benefits, or change immigration status.
Simple explanation
An ITIN and SSN are both individual identifiers, but they are not interchangeable for every program or purpose. ITIN eligibility is based on a federal tax purpose and SSN ineligibility, not simply non-U.S. citizenship.
Why it happens
An ITIN can help an eligible individual meet a federal tax filing or reporting requirement. It is not an immigration document, work authorization, a business EIN, or a general-purpose identification number. If an ITIN is not used on a federal return for three consecutive tax years, it expires after the third year of non-use and generally must be renewed before it is included on a return.
How an ITIN is used
- 1
Confirm you have a federal tax purpose
Examples can include a filing requirement, an allowable tax benefit, a treaty claim, or another federal tax reporting need.
- 2
Confirm you are not eligible for an SSN
If eligible for an SSN, apply for an SSN instead. The IRS does not issue an ITIN merely as a substitute for a number that is available to you.
- 3
Use Form W-7 and current IRS instructions
The application usually requires identity documents and supporting tax documentation. Check whether an exception applies before mailing anything.
- 4
Check whether the ITIN has expired
An ITIN not used on a U.S. federal tax return for three consecutive tax years expires after the third year of non-use. Renew an expired ITIN before including it on a federal return.
Key takeaways
- An ITIN is for an individual with a federal tax purpose who is not eligible for an SSN.
- It is for federal tax purposes only and does not authorize work or change immigration status.
- Form W-7 is the IRS application; eligibility and supporting documents depend on the applicant.
- An ITIN can expire after three consecutive tax years of non-use and may need renewal before use on a return.
Frequently asked questions
Does an ITIN provide work authorization?
No. An ITIN is for federal tax purposes only. It does not authorize employment, provide Social Security benefits, or change immigration status.
Does an ITIN expire?
An ITIN not used on a U.S. federal tax return for three consecutive tax years expires on December 31 after the third tax year of non-use. If an expired ITIN will appear on a federal tax return, renew it first.
Can an ITIN be used instead of an EIN?
No. An ITIN identifies an individual; an EIN identifies a business or other entity. One person or business may need one or both depending on tax status and filing requirements.
Is an ITIN a general ID for opening accounts?
No. It is not a general-purpose identity document; financial institutions set their own customer-identification requirements.
Related guides
Official sources
- IRS: Individual taxpayer identification number (ITIN)
Who may need an ITIN, what it is for, and what it does not authorize or provide.
- IRS: How to renew an ITIN
An ITIN not used on a U.S. federal return for three consecutive tax years expires after the third tax year of non-use; renewal is needed before use on a return.
- IRS: About Form W-7
Official application form and current instructions.
Educational information only; not individualized legal, tax, accounting, or financial advice. Rules can change and results depend on your facts. Check current official guidance or consult a qualified professional.