How to apply for an ITIN

An Individual Taxpayer Identification Number (ITIN) is a 9-digit number the IRS issues for federal tax purposes to people who are not eligible for a Social Security number. You apply with Form W-7, Application for IRS Individual Taxpayer Identification Number, and in most cases you attach a US federal tax return to the same package. There are three ways to get the package to the IRS.

The first way is mail. You send the completed Form W-7, the tax return, and original supporting documents (or certified copies from the issuing agency) to the IRS ITIN Operation in Austin, Texas. The IRS uses the Austin address for regular mail and a separate street address for private delivery services. This route costs nothing beyond postage, but your original documents travel through the mail in both directions.

The second way is in person at an IRS Taxpayer Assistance Center (TAC) that offers ITIN services. This is also free. A TAC can authenticate your documents while you wait, except school and medical records for dependents, which must still be mailed with the application. Appointments can take several weeks to get, so plan ahead, and check that the center you pick offers ITIN services before you go.

The third way is through an IRS-approved acceptance agent, in the US or abroad. Agents help you complete Form W-7 and mail the package for you, and fees vary by agent. A certifying acceptance agent can authenticate most of your documents and hand them straight back, so only the exceptions travel by mail. A plain acceptance agent reviews your documents and mails the originals with the package. Either kind of agent can work with the IRS to resolve problems with your application.

After you apply, the IRS mails your assigned ITIN on a CP565 notice and returns your documents within 60 days. You cannot hold an ITIN and a Social Security number at the same time: once you get an SSN, stop using the ITIN and notify the IRS so your tax records are combined under the SSN.