How to Apply for an ITIN: A Complete Step-by-Step Guide

If you need to file a U.S. tax return but aren’t eligible for a Social Security number, you need an Individual Taxpayer Identification Number (ITIN). The process trips up thousands of applicants every year — here’s exactly how to do it right the first time.

What Is an ITIN — and Who Needs One?

An ITIN is a nine-digit number (always starting with 9) issued by the IRS solely for tax purposes. You need one if you must file a U.S. return or be listed on one, but can’t get an SSN. Common situations include:

• Non-resident aliens with U.S.-source income (rental property, investments, business income)
• Spouses and dependents of U.S. citizens or resident aliens
• Foreign owners of U.S. LLCs who must file U.S. returns
• Students, researchers, and others claiming tax treaty benefits

Important: an ITIN does not authorize work in the U.S., change immigration status, or qualify you for Social Security benefits. It exists for tax filing only.

Step 1: Complete Form W-7

Form W-7 is the ITIN application. You’ll select your reason for applying (the lettered boxes a–h), provide your legal name exactly as it appears on your passport, foreign address, date and place of birth, and the U.S. visa information if applicable. The most common rejection reason is a mismatch between the W-7 and supporting documents — triple-check every field.

Step 2: Attach Your Federal Tax Return

Unless you qualify for a specific exception, a complete federal tax return must be attached to the W-7. Leave the SSN field blank where the ITIN will go. This is where most DIY applications fail — the return and W-7 must be consistent and both must be signed.

Step 3: Prove Identity and Foreign Status

The IRS accepts 13 document types, but only one proves both identity and foreign status by itself: a valid passport. Without a passport, you generally need a combination such as a national ID card plus a foreign birth certificate. Documents must be current and — here’s the hard part — either originals or certified copies from the issuing agency. Photocopies and notarized copies are rejected.

Step 4: Submit — Without Mailing Your Passport

You have three options:

• Mail everything to the IRS ITIN office in Austin, TX — including your original passport, which the IRS holds for up to 60 days. Risky if you travel.
• IRS Taxpayer Assistance Center — in-person review by appointment; documents are verified and returned immediately.
• Certifying Acceptance Agent (CAA) — an IRS-authorized professional who verifies your documents in person or by video, so you keep your passport. This is the safest and most convenient route for most applicants.

Working with a CAA means your original documents never leave your hands — and a professional checks your application before the IRS ever sees it, virtually eliminating rejections.

Step 5: Wait for Your CP565 Notice

Processing takes about 7 weeks normally, and 9–11 weeks during tax season (January–April) or for applications from abroad. Approved applicants receive IRS Notice CP565 with the new ITIN. If something’s wrong, you’ll get a rejection notice explaining why — and the clock starts over.

Don’t Forget Renewal

ITINs expire if not used on a federal return for three consecutive years, and middle digits 70–88 and 90–99 (depending on assignment period) have already expired. An expired ITIN used on a return means delayed refunds and lost credits until renewal — renew with the same W-7 process before filing.

Get It Done Right the First Time

Alpha Tax Pros prepares ITIN applications and renewals, reviews your supporting documents, and files the attached tax return correctly — so your application is approved once, instead of rejected twice. Book a free consultation and we’ll map out your exact situation.