An ITIN — an Individual Taxpayer Identification Number — is a nine-digit number the IRS issues to people who need to file a U.S. tax return but are not eligible for a Social Security number. It always begins with a 9, and it exists for exactly one purpose: letting someone meet a federal tax obligation.
That narrow purpose is the part people most often misunderstand. An ITIN is not a work permit. It does not grant immigration status, and it does not make someone eligible for Social Security benefits. It is a filing number, nothing more. But for hundreds of thousands of families, it is the only way to file a return, claim the credits they are owed, and build the documented tax history that immigration attorneys and lenders frequently ask for later.
We prepare ITIN applications at our Providence office year-round, and the same handful of problems account for nearly every rejection we see. Here is what actually matters.
The short version
- You need an ITIN if you have a U.S. filing requirement but cannot get a Social Security number.
- You apply with Form W-7, and it normally goes in attached to a tax return — not on its own.
- The IRS wants original documents or certified copies from the issuing agency. Regular photocopies get rejected.
- A Certifying Acceptance Agent can verify your passport so you do not have to mail the original.
- ITINs expire. One that has not appeared on a return for three consecutive years goes inactive.
Who actually needs one
The test is not immigration status — it is whether you have a U.S. tax filing obligation and are ineligible for an SSN. In practice, that usually means one of these situations:
- You earn income in the United States and have to file a federal return, but you are not authorized for an SSN.
- You are the spouse of a U.S. citizen or resident and you are filing a joint return.
- You are a dependent being claimed on someone else's return and you do not qualify for an SSN.
- You are a nonresident who has to file because of U.S. investment, rental, or business income.
- You are a nonresident claiming a reduced rate of withholding under a tax treaty.
If you are eligible for a Social Security number, you cannot get an ITIN — and you should not try. Apply for the SSN instead. If an application is pending with the Social Security Administration, wait for it to resolve before filing Form W-7.
An ITIN issued to you does not change what your employer must do, and it does not authorize employment. It is strictly a number for filing and paying taxes.
Form W-7, and the mistake almost everyone makes
The application itself is Form W-7. It asks for your name, your foreign address, your birth information, and — critically — the reason you are applying, which you indicate by checking one of the lettered boxes at the top.
The mistake we see constantly: people mail Form W-7 by itself. In most cases the IRS will not process it that way. The W-7 is meant to travel with the tax return it enables. You assemble the return, leave the SSN field for that person blank, attach the W-7 and the supporting identity documents on top, and mail the whole package to the IRS ITIN operation in Austin, Texas — not to the address printed in the regular return instructions.
There are exceptions where a W-7 can be filed on its own, mostly involving tax treaty benefits, third-party withholding on passive income, and mortgage interest reporting. Each exception has its own documentation requirement. If you think one applies to you, get it confirmed before you mail anything, because a wrongly-filed standalone W-7 comes back rejected months later.
The documents the IRS will accept
This is where most applications die. The IRS requires original documents or copies certified by the agency that issued them. A photocopy you made, and even a copy notarized by a notary public, will be rejected.
| Document | Proves identity | Proves foreign status |
|---|---|---|
| Passport (valid) | Yes | Yes — the only stand-alone document |
| National identification card | Yes | Yes |
| Foreign birth certificate | Yes | Yes, if issued by a foreign country |
| Foreign driver's license | Yes | No |
| U.S. driver's license | Yes | No |
| Foreign voter registration card | Yes | Yes |
| Visa issued by the U.S. Dept. of State | Yes | No |
A valid passport is the only document that satisfies both requirements by itself. Without one, you need two documents from the list — one establishing identity and one establishing foreign status. Dependents have additional requirements, and for dependent children a foreign birth certificate is usually part of the package.
How to avoid mailing your passport
Understandably, almost nobody wants to put their original passport in the mail and wait months to get it back. There are two ways around it.
The first is a Certifying Acceptance Agent — a person or firm authorized by the IRS to examine your original documents, verify them, and submit a certificate of accuracy in place of the originals. You keep your passport. This is the route most of our clients take, and it is the single biggest reason applications go smoothly.
The second is an appointment at an IRS Taxpayer Assistance Center that offers document authentication. Appointments are required, and availability varies considerably.
The third option — mailing originals to Austin — works, but plan on being without those documents for a substantial stretch, and never do it if you have travel coming up.
Expiration and renewal
ITINs do not last forever. If an ITIN has not been included on a federal tax return for three consecutive tax years, it goes inactive at the end of the third year. Certain older ITINs, grouped by their middle digits, were also retired on a rolling schedule in past years.
An expired ITIN does not stop you from filing — but the return gets processed without any credits or exemptions that depend on that number, and the refund is held until the ITIN is renewed. For a family claiming child-related credits, that can mean thousands of dollars sitting in limbo for months.
Renewing uses the same Form W-7, with the renewal box checked, and the same document standards. You can renew before filing season starts, which is the sensible time to do it — the IRS processes renewals considerably faster in the fall than in the middle of filing season.
If anyone on your return — you, your spouse, or a dependent — has an ITIN that has gone inactive, renew it before you file. Filing first and renewing after is what turns a three-week refund into a six-month wait.
How long it takes
Outside of filing season, applications generally move in a matter of weeks. During filing season, from late January through April, processing slows considerably as volume spikes. Applying in the fall, when you have the option, is meaningfully faster.
When the ITIN is issued, the IRS mails a notice with the number. Keep that notice. You will be asked for it more often than you expect — by employers handling tax reporting, by banks, and by anyone preparing your return in a future year.
Getting help with it
ITIN applications are unforgiving in a specific way: the rejections are slow. You do not find out something was wrong for weeks or months, and by then the filing deadline may have passed. Getting the documentation right the first time is worth far more than the time it seems to save doing it alone.
We handle W-7 applications and renewals alongside the returns they attach to, in English and Spanish, at our office on Broad Street in Providence. If you are unsure whether you need an ITIN at all, that conversation takes about ten minutes and costs nothing.
For the official IRS instructions, see the IRS ITIN page and the Form W-7 instructions.