When is an ITIN useful as a taxpayer?

What is an ITIN number?

An ITIN is a 9-digit tax processing number issued by the IRS to individuals who:

  1. Are not eligible for a Social Security Number
  2. Need a U.S. taxpayer ID to:
  • File taxes
  • Claim tax treaty benefits
  • Report U.S. income
  • Be claimed as a dependent/spouse on a U.S. return


Format: 9XX-7X-XXXX or 9XX-8X-XXXX


Step-by-Step: How to Apply for an ITIN


1. Complete Form W-7

Download: Form W-7 (IRS website)

Fill out completely and accurately

Select the appropriate reason code

 (e.g., “a” for nonresident with U.S. income, “b” for spouse/dependent)

Must be filed with your U.S. tax return, unless you qualify for an exception (see below).


2. Provide Valid Identification Documents

You must include original documents OR certified copies from the issuing agency.

Primary document:

  • Passport (most common and preferred — only document that proves both identity and foreign status)


OR


Two of the following (one must have photo):

  • National ID card
  • U.S. or foreign driver’s license
  • Birth certificate (for dependents)
  • School records (for minors)
  • Visa or U.S. immigration documents (ex. I-94)


3. Alternatively: Apply in Person (Optional but Safer)

You can apply without mailing original documents if you:


Option 1: Use a Certified Acceptance Agent (CAA)

These are IRS-authorized agents who verify documents and help with Form W-7.

No need to mail passport/originals.

Find a CAA near you


Option 2: Apply at an IRS Taxpayer Assistance Center (TAC)

You can make an appointment and apply in person.

Bring original documents.




4. Common Reasons You Might Need an ITIN


Reason W-7 Code Notes
Filing U.S. taxes with U.S. income but no SSN a Must attach return
Spouse or dependent of a U.S. citizen/resident alien d Often needed for joint returns
Claiming tax treaty benefits (e.g., students, teachers, researchers) b May qualify for exception to filing return
Nonresident alien required to file U.S. return a Must have U.S. income (e.g., rental, consulting, investing)

Processing Time

6 to 12 weeks(can take longer during tax season or if documents are incomplete)


You’ll receive a letter in the mail with your ITIN


Renewing an ITIN?


ITINs expire if:

  • Not used on a return for3 consecutive years
  • Have middle digits 88 or others that the IRS designates
  • Use Form W-7 and check the renewal box.


Important Notes

  • ITIN does NOT authorize work in the U.S.
  • ITIN does NOT provide immigration status
  • Never use an ITIN where an SSN is required