How to apply for your ITIN, step by step

What an ITIN is, and what it’s for

The Individual Taxpayer Identification Number (ITIN) is a nine-digit number the IRS issues to people with U.S. tax obligations who don’t qualify for a Social Security number. It looks like an SSN in format (it always starts with a 9), but it carries no work authorization and no connection to your immigration status.

With an ITIN you can file your tax return, open a bank account, form an LLC, get credit cards and start building a U.S. credit history. For the full picture — including exactly how it differs from an SSN — see our complete ITIN guide.

Who can apply

The IRS issues ITINs to anyone with a U.S. tax obligation who doesn’t qualify for an SSN, regardless of immigration status. In practice, that covers:

• Nonresident aliens with U.S.-source income who must file.
• U.S. residents (under the substantial presence test) without an SSN.
• Spouses and dependents of U.S. citizens or residents claimed on a return.
• Owners or members of an LLC who need an individual tax identifier.
• Foreign students, teachers or researchers with specific tax obligations.

What to have ready before you start

Gather this before filling anything out, so you don’t have to start over mid-application:

• A completed Form W-7 (the official ITIN application)
• A valid passport — or two alternate documents, one with a photo
• Your tax return for the current year (in most cases it’s filed together with the W-7)
• Extra supporting documents if your category requires them (dependents’ birth certificates, proof of residency, and so on)

The 8 complete steps

Here’s the process end to end. Treat it as a checklist: skip a step and the IRS will likely send the application back, costing you weeks.

1. Work out your applicant category

   Form W-7 asks you to check a “Reason for applying.” The most common ones we see: (b) nonresident alien filing a U.S. tax return, (c) resident alien filing a return, (d) dependent of a U.S. citizen or resident, and (e) spouse of a citizen or resident. Checking the wrong category is one of the top reasons for rejection — if in doubt, confirm with a professional before mailing.

2. Fill out Form W-7, field by field

   Download the official Form W-7 from the IRS and complete it with your name exactly as it appears on your passport, your current mailing address (no P.O. Box for the foreign address, where it applies) and your date of birth in month/day/year format. Sign and date it — an unsigned W-7 is rejected automatically.

3. Gather your identification documents

   A valid passport is the only document that proves identity and foreign status on its own. Without one, the IRS accepts combinations of two other documents (for example, your country’s photo ID plus a birth certificate), and at least one must carry a photo. Copies must be legible and — unless you work with a Certified Acceptance Agent — certified by the issuing agency.

4. Decide how your documents will be verified

   Three roads: (A) by mail to the IRS, sending your original passport or certified copies — they return it, but you go weeks without it; (B) through a Certified Acceptance Agent (CAA), who verifies your document and your passport never goes to the government; or (C) at an IRS Taxpayer Assistance Center (TAC) by appointment. For most people, a CAA is the right balance of safety and speed.

5. Prepare your tax return

   In most cases the W-7 doesn’t travel alone: it goes attached to your tax return for the year, such as Form 1040. That’s the proof the IRS wants that you actually need the ITIN to meet a tax obligation. The W-7 instructions document a few exceptions (certain tax-treaty benefits, for example) where you can apply without a return.

6. Send the complete package

   Bundle the Form W-7, your tax return and your identification (originals, certified copies, or your CAA’s certification) into one package. Mailing it yourself? Use tracking. Working with a CAA? The CAA assembles and mails the package to the IRS ITIN Operations Center for you.

7. Receive your ITIN

   The IRS processes complete applications in 6 to 8 weeks in regular season, and 9 to 11 from February through April, when volume climbs. Your ITIN arrives by mail in a letter (CP565 when approved). If the IRS needs more information or finds an error, it sends a CP566 asking you to correct and resubmit.

8. Put it to work on your next return

   Your ITIN is active from the day you receive it. Use it in place of a Social Security number on your next tax return and in anything that requires it. Go three consecutive years without using it on a federal return and the IRS deactivates it — you’d have to renew before using it again.

Option B, in detail: applying through a Certified Acceptance Agent (CAA)

Of the three ways to verify your documents, working with a Certified Acceptance Agent is the only one where your passport never goes to the government. A CAA is authorized directly by the IRS to verify your identity — reviewing your document, confirming the copy attached to the W-7 is correct, and certifying that verification to the IRS. At Right Step we work as CAAs: in our Austin office you keep your passport in hand, and by mail from any state it travels only to us, with tracking and required signature, and ships back within 24 hours of your video interview.

The errors that stall applications

The IRS rejects or returns a significant share of the W-7s it receives — almost always for avoidable mistakes:

• A name that doesn’t match the passport: A dropped middle name, surnames in the wrong order, or an extra initial are frequent causes of rejection. The name on the W-7 must copy your identity document exactly.
• The wrong applicant category: Checking “dependent” when you’re actually applying as a spouse (or the reverse) forces the IRS to send the application back for correction — losing you weeks.
• Expired documents or uncertified copies: An expired passport doesn’t work, and copies mailed without certification (when you’re not using a CAA or a TAC) get rejected.
• Missing the tax return when it’s required: Unless your case fits one of the IRS exceptions, a W-7 mailed without the return attached comes back unprocessed.
• An incomplete address, or a P.O. Box as the foreign address: The IRS requires a complete physical address; a P.O. Box isn’t valid as the “foreign address” on the form.
• No signature or date: It sounds obvious, but it’s among the most common rejection reasons — check every required signature before sending.

What it costs, and how long it takes

After your ITIN arrives

The ITIN is almost never the end of the road — it’s usually the first step of something bigger. The most common next moves:

• File your return correctly with the new number: see taxes with an ITIN.
• Start building credit with it: see how credit with an ITIN works.
• Still unsure what an ITIN can and can’t do next to an SSN? Read the full comparison.

Do it yourself, or with a professional?

Both are legitimate — it comes down to how much time you have and how much risk you’re willing to carry:

• On your own: you pay the IRS nothing, but you carry the risk of an error in the category, the form or the documents — and every correction adds weeks. Mail your documents yourself and you also go without your original passport while the IRS processes it.
• With a Certified Acceptance Agent: you pay for the service, but your passport never goes to the government, someone reviews your form before it ships, and you have a person to call if the IRS asks for a correction.

Rather skip the errors and the extra weeks? We file ITINs as IRS Certified Acceptance Agents — in Austin or by mail from any state →