ITIN Guide: Getting Tax IDs for a Nonresident Spouse or Dependents

An ITIN — Individual Taxpayer Identification Number — is the tax ID the IRS issues to people who need to be on a US tax return but can't get a Social Security number. The most common case by far: you want to file jointly with a spouse who has no SSN. The core mechanics surprise people: you apply with Form W-7, and you file it attached to your actual tax return — not months in advance on its own.

This guide covers who actually needs an ITIN, the application routes (including how to avoid mailing your spouse's original passport to the IRS), renewals, the rejections we see most, and an honest word about dependents living abroad. It's a companion to The NRI's Complete Guide to US Taxes.

Who actually needs an ITIN

• A nonresident spouse joining a joint return. The classic scenario: you're a US tax resident, your spouse is a nonresident with no SSN, and you make the §6013 election to file jointly as full-year residents. The joint return can't be filed without a taxpayer ID for both spouses, so the W-7 rides along with it. The election itself — and when it beats dual-status filing — is covered in our dual-status return guide.
• Dependents you can claim, where a tax benefit applies. A dependent goes on the return only with a tax ID, and an ITIN application must show a live tax purpose — a credit or filing benefit that the dependent's presence on the return actually produces.
• Nonresidents with US filing obligations of their own — a 1040-NR for US rental income or other US-source income, or treaty-based claims — who aren't eligible for an SSN.

Who does not need one: anyone eligible for an SSN. If your spouse has work authorization, the SSN is the right ID — the IRS will reject a W-7 from an SSN-eligible applicant.

The honest part: dependents living outside the US

This is where expectations need managing. Dependents who live outside the United States generally cannot be claimed on a US return. Children living with grandparents in India, parents you support in India — living abroad, they generally don't qualify as dependents at all, with narrow exceptions (residents of Canada and Mexico under specific rules, and certain other limited cases). Beyond that, key credits carry their own ID rules — the Child Tax Credit, for example, requires the child to have an SSN, not an ITIN.

If a preparer promises refunds built on ITINs for family members living in India, walk away. Applications without a genuine tax benefit get rejected — and claims without a legal basis invite worse.

How the application works

Form W-7 asks for the applicant's identity and foreign status, and must be supported by original documents or certified copies. The passport is the one document that proves both identity and foreign status on its own. You have three routes:

1. Mail originals to the IRS ITIN operation. It works, but it means your spouse's actual passport sits in the mail and in IRS processing — weeks at minimum. If travel is on the calendar, this route is a genuinely bad idea.
2. Use a Certifying Acceptance Agent (CAA). A CAA is authorized by the IRS to verify the passport and certify the copy, so the original never leaves your hands. The CAA reviews documents, certifies them, and submits the W-7 package with your return. For most families this is the clearly better route.
3. Get certified copies from the issuing agency. A copy certified by the passport-issuing authority also satisfies the IRS. Feasible, but often slower and clumsier than the CAA path.

Whichever route: the W-7 package attaches to the front of the paper-filed return, which goes to the ITIN unit rather than the normal filing address. The IRS processes the ITIN first, then the return — so expect the whole thing to take noticeably longer than a normal e-filed return. Timelines vary with the season; build in patience and don't count on the refund by any particular date.

Renewals and expirations

ITINs aren't permanent. An ITIN that goes unused on a federal return for several consecutive years expires, and an expired ITIN on a return delays processing and can hold up credits until it's renewed — also via W-7, with documents again. If your spouse's ITIN has sat unused (say, you filed separately for a few years), check its status before the next joint return rather than after the IRS bounces it.

The rejections we see most

• Filing the W-7 alone, without the return — outside of narrow exceptions, the application needs the return attached. Standalone W-7s come back.
• Uncertified photocopies — an ordinary passport copy, even notarized, doesn't qualify. Certification must come from a CAA or the issuing agency.
• Expired documents — the passport must be current.
• An SSN-eligible applicant — work-authorized spouses should apply for the SSN instead.
• No tax benefit shown — dependent applications with no credit or benefit attached to the return.
• Name and date mismatches — the W-7, passport, and return must agree exactly. Transliteration inconsistencies (one document with a middle name, one without) are a classic avoidable bounce.

A rejection isn't fatal — you fix and refile — but each round costs weeks. Getting the package right the first time is most of the value a CAA or preparer adds. And since ITIN returns are commonly first-year returns, they often travel with the rest of the arrival-year stack — residency elections and the disclosure forms covered in our first-year H-1B tax guide.

The bottom line

If you're filing jointly with a spouse who can't get an SSN, plan the ITIN into the filing itself: W-7 attached to the return, passport certified through a CAA so the original stays home, names matching to the letter — and honest expectations about dependents abroad. Taxagon's CPAs and EAs prepare ITIN packages alongside first-year and NRI returns every season — if your joint return is waiting on a tax ID, our NRI services team can handle the whole package.

This article is general information, not tax advice for your specific situation. Tax law changes; figures are for the years stated.