ITIN: what it is, who needs one, and how to apply

What an ITIN is — and is not

An Individual Taxpayer Identification Number is a nine-digit number, beginning with 9, that the IRS issues to people who need a US taxpayer identification number for federal tax purposes but are not eligible for a Social Security number. That is the whole job. It lets the IRS process a return, a treaty claim or a withholding form that has your name on it.

It is easy to over-read. An ITIN does not authorize you to work in the US, does not confer or change immigration status, does not qualify you for Social Security benefits or the Earned Income Tax Credit, and is not valid identification outside the federal tax system. It is also not a fallback for people who could get an SSN: the IRS tells you not to apply if you have or are eligible for one, and if you later receive an SSN you must stop using the ITIN and tell the IRS so it can combine your records.

Who typically needs one

For most readers of this site, the ITIN question comes up for a family member rather than the visa holder. The usual cases:

• H-4, F-2 and other dependents with no work authorization who will appear on a US return — most often a spouse on a joint return, or a child claimed for a credit that accepts an ITIN.
• A nonresident spouse being treated as a resident under the joint-return election described in the resident vs nonresident guide. The election is not valid without an SSN or ITIN for that spouse.
• Nonresidents with US-source income and no SSN — an owner abroad renting out a US property, someone selling US real estate, or an investor claiming a reduced treaty rate on a withholding certificate.
• Dependents of a resident filer who are claimed for an allowable tax benefit, such as the Credit for Other Dependents or head-of-household filing status.
• Nonresident students, professors and researchers who must file a return or claim a treaty exemption but have no US employment and so cannot get an SSN.

The dependent rule has teeth. A spouse or dependent is not eligible for an ITIN — or a renewal — unless they are claimed for a specific tax benefit on the return. Writing a child’s name on the return is not enough; the benefit box has to be checked. Check the rules of the credit you are after, too. The Child Tax Credit requires both you and the child to have Social Security numbers valid for employment, so a child with an ITIN cannot unlock it — though the same child can qualify you for the Credit for Other Dependents, which does accept an ITIN.

SSN or ITIN? Settle eligibility first

The IRS rule is blunt: do not complete Form W-7 if you have an SSN or are eligible to get one. Eligibility is set by immigration status, not by whether you have started a job yet. Anyone whose status permits work — H-1B, L-1, TN, O-1 and E-2 principals, dependents holding an Employment Authorization Document, and F-1 students once they have authorized employment such as an on-campus job, CPT or OPT — should apply to the Social Security Administration. An ITIN application from an SSN-eligible person is rejected, and the time spent is lost.

If your situation is genuinely uncertain, resolve it with SSA before you touch the W-7. Do not run the two applications in parallel.

Form W-7 and the three ways to apply

Every ITIN application is Form W-7, Application for IRS Individual Taxpayer Identification Number, plus documents proving identity and foreign status, plus — in most cases — the federal tax return the number is needed for. One W-7 per applicant: a family of three applying together files three forms with one return. You have three ways to submit the package.

1. By mail to the IRS ITIN Operation in Austin, Texas, with the return and either original documents or copies certified by the agency that issued them. Cheapest, slowest, and the route most people regret when it means posting a passport.
2. In person at an IRS Taxpayer Assistance Center, by appointment. Staff review the W-7 and can authenticate most supporting documents on the spot, so the originals go home with you. There is no charge, but you need an appointment.
3. Through a Certifying Acceptance Agent — a tax professional or firm authorized by the IRS to complete the W-7, authenticate your documents, return them to you immediately and mail the package on your behalf. CAAs charge a fee. For dependents they can authenticate only passports and birth certificates; any other dependent document still has to go to the IRS.

Whichever route you use, the document standard is the same. A valid passport is the only document that proves both identity and foreign status on its own. Without one you need two documents from the list in the W-7 instructions — a national ID card, a foreign driver’s license, a birth certificate and so on — and the combination has to cover both identity and foreign status.

Dependents have an extra hurdle. A child’s passport only works as a standalone document if it shows a US date of entry. If it does not, you must add proof that the child lives in the US — school records, medical records or a state ID, depending on age. The W-7 instructions carve out exceptions for dependents from Canada and Mexico and for the families of US military personnel stationed abroad.

Timing: file it with your return

A W-7 is normally filed with the tax return that needs it, not ahead of it. You prepare the complete return, leave the SSN box blank for each applicant, attach the W-7 forms and documents, and send the whole package to Austin or hand it over at the TAC or to your CAA. The IRS assigns the numbers, processes the return, and posts the ITIN letters to you. That means the return goes in on paper, and any refund waits for the number.

The exceptions to the with-a-return rule are narrow and listed in the W-7 instructions: certain third-party withholding on passive income, scholarship and treaty claims by students and researchers, mortgage-interest reporting, US real estate sales, and a few others. If none applies to you, a W-7 mailed on its own comes back unprocessed.

Plan on about seven weeks to hear back, and nine to eleven weeks if you file between mid-January and the end of April or from overseas. Filing on April 14 with a W-7 attached is allowed; it is also the slowest possible path, because your package lands in the peak-season queue.

Expiry and renewal

ITINs expire through disuse. If an ITIN is not used on a US federal tax return for any three consecutive tax years, it expires on December 31 after the third year of non-use. An ITIN that appears only on information returns you receive — a 1099 for bank interest, say — does not need renewing for that purpose. It only has to be renewed if it is going to appear on a tax return.

Renewal is the same Form W-7 with the “Renew an existing ITIN” box checked, the same document rules, and no tax return required. If you know the number has lapsed, renew before you file: a return that arrives with an expired ITIN is delayed while the IRS sorts out the number, and credits tied to that person may be held back until the renewal comes through.

What an ITIN does — and does not — do for banking and credit

Federal customer-identification rules allow a bank to accept an ITIN, a passport number or another government ID number as the identifying number on a new account, so many banks and credit unions will open a checking account for an ITIN holder. Policies vary by institution, and the ITIN is only the identifier, not the reason you are approved. Our banking guide covers what to bring and what to ask before you sign.

Credit is murkier. The credit bureaus do not require an SSN to build a file — a lender that reports under an ITIN will create one, and some card issuers accept ITIN applications. But fewer lenders lend or report on an ITIN, and if you later get an SSN you should tell each bureau so the history moves with you rather than staying orphaned under the old number. If you are SSN-eligible, get the SSN first; it opens every door the ITIN opens and many it does not. If you are not, the build-credit guide walks through the sequence that works without one.

Common mistakes

• Applying for an ITIN when you are SSN-eligible, or running both applications at the same time.
• Mailing a W-7 without the tax return and without qualifying for a listed exception.
• Requesting an ITIN for a dependent who is not claimed for a specific tax benefit on the return.
• Sending a child’s passport with no US entry stamp and no school or medical records to back it up.
• Posting the family’s only passport the month before an international trip.
• Assuming the ITIN on last year’s return is still active without checking the three-year rule.
• Continuing to use the ITIN after receiving an SSN instead of asking the IRS to merge the records.

Other guides on this site

An ITIN is usually one step inside a larger question. These pick up the rest of it:

• Resident vs nonresident alien — the status test that decides whether a joint return, and the spouse election, is even on the table.
• Build US credit as an immigrant — the sequence that gets you a usable score, with or without an SSN.
• H-1B taxes explained — withholding, FICA and filing status for the household’s main earner.