What Is an ITIN? A Plain Guide to Form W-7

Many families and workers in Brownsville and the Rio Grande Valley have a U.S. federal tax filing responsibility but are not eligible for a Social Security number. For them, the IRS issues an Individual Taxpayer Identification Number, or ITIN. This guide explains what an ITIN is, how the application on Form W-7 works, which documents the IRS asks for, and what to know about renewals. Everything below comes from IRS publications and pages, which are linked so you can read the original wording.

What an ITIN is

According to the IRS, an ITIN is a tax processing number issued by the Internal Revenue Service for certain resident and nonresident aliens, their spouses, and their dependents. It is a nine-digit number that begins with the number 9 and is formatted like a Social Security number (IRS Publication 1915).

The IRS states that an ITIN is issued for federal tax purposes only (IRS: Individual Taxpayer Identification Number). The IRS also states that an ITIN does not qualify you for Social Security benefits or the Earned Income Tax Credit, does not provide or change immigration status, and does not authorize you to work legally in the U.S. Publication 1915 also notes that ITINs are issued regardless of immigration status, because both resident and nonresident aliens may have U.S. federal tax filing and payment responsibilities.

Who uses Form W-7

Form W-7, Application for IRS Individual Taxpayer Identification Number, is the form used to request a new ITIN or to renew an existing one. A Spanish version, Form W-7(SP), is also available. The IRS explains that the ITIN is for people who need a U.S. taxpayer identification number for tax purposes but do not have, and are not eligible to obtain, a Social Security number (Instructions for Form W-7).

If a person has a Social Security number, or is eligible to get one, they should not apply for an ITIN.

Step by step: how the application works

Step 1: Confirm the tax purpose

The IRS requires a federal tax reason for every ITIN application. In most cases, that reason is filing a U.S. federal income tax return. The Form W-7 instructions list the reasons that can be selected on the form and describe a limited set of exceptions to the tax return requirement (Instructions for Form W-7).

Step 2: Prepare the tax return

Generally, Form W-7 must be attached to a valid federal income tax return, unless the applicant qualifies for an exception or is renewing an ITIN (IRS Publication 1915). The ITIN is entered on the return in the space provided for the Social Security number once it is issued.

Step 3: Gather identity and foreign status documents

Applicants must prove both identity and foreign status. The W-7 instructions state that there are 13 acceptable documents, and the passport is the only stand-alone document, meaning it can establish both identity and foreign status by itself. For certain dependents, a passport without a date of entry into the United States is not accepted as a stand-alone document (Instructions for Form W-7).

Documents must be current (not expired at the time you submit the application) and must be originals or copies certified by the issuing agency. The instructions give the full table of acceptable documents and what each one can establish.

Step 4: Choose how to submit

The IRS describes three ways to submit an application (IRS: Individual Taxpayer Identification Number; Instructions for Form W-7):

• By mail, to the IRS ITIN Operation address in Austin, Texas listed in the W-7 instructions. The instructions say not to use the mailing address shown in the instructions for your tax return.
• In person at a designated IRS Taxpayer Assistance Center (TAC), by appointment.
• Through an IRS-authorized Certifying Acceptance Agent (CAA), who can review certain documents.

The W-7 instructions note that if you will need your documents for any purpose within 60 days of submitting your application, you may wish to apply in person at a TAC or with a CAA. If mailed original documents are not returned within 60 days, the instructions say you can call the IRS.

Step 5: Wait for the IRS response

The IRS states that it allows 7 weeks to notify you about your ITIN application status, and that it can take 9 to 11 weeks during tax season (January 15 to April 30) or if you applied from overseas (IRS: Individual Taxpayer Identification Number, page last reviewed October 28, 2025; checked October 10, 2026).

What to gather before you start

• The current version of Form W-7 or W-7(SP) from irs.gov
• The completed federal income tax return the ITIN is needed for, unless an exception applies
• A valid passport, or a combination of other acceptable documents from the W-7 instructions table
• Originals or copies certified by the issuing agency (not ordinary photocopies)
• For dependents, any additional documents the W-7 instructions require
• For a renewal, your existing ITIN and the reason for renewing

Things to know about renewals

The W-7 instructions state that if an ITIN is not included on a U.S. federal tax return at least once for the last 3 consecutive tax years, it expires on December 31 of the third consecutive tax year, and it must be renewed before being used again on a U.S. federal tax return (Instructions for Form W-7). The IRS says to renew an ITIN if it expired and you need to file a U.S. federal tax return.

Common mistakes the IRS instructions address

• Using an older form. IRS Publication 1915 says to apply using the most current Form W-7 or W-7(SP).
• Sending plain photocopies. The instructions require originals or copies certified by the issuing agency.
• Mailing to the wrong address. The W-7 has its own mailing address, separate from the tax return instructions.
• Leaving out the tax return. Unless an exception or renewal applies, the return must be attached.
• Applying when eligible for an SSN. People who have or can get a Social Security number should not file Form W-7.

Frequently asked questions

Does an ITIN let me work in the United States?

No. The IRS states that an ITIN is for federal tax purposes only and does not authorize work in the U.S.

Is there a Spanish version of the form?

Yes. Form W-7(SP) is the Spanish version of the application, and IRS Publication 1915 is also available in Spanish.

Can I keep my passport while I apply?

The W-7 instructions say that if you need your documents within 60 days, you may wish to apply in person at an IRS Taxpayer Assistance Center or through a Certifying Acceptance Agent, rather than mailing originals.

How long does it take?

The IRS says to allow 7 weeks to be notified, or 9 to 11 weeks during tax season or for applications from overseas.

When does an ITIN expire?

An ITIN not used on a federal tax return at least once in the last 3 consecutive tax years expires on December 31 of the third year, according to the W-7 instructions.

Where can I read the official rules?

The Instructions for Form W-7 and IRS Publication 1915 are the primary IRS sources.

Questions in the Rio Grande Valley

Garduño Tax & Associates works with individuals, families and small businesses in Brownsville and South Texas. If you have questions about the ITIN process or the documents the IRS asks for, you can contact our office to talk through your situation.