Once you've completed Form W-7, where you actually send it depends on which of the three IRS-approved channels you use. This page focuses specifically on the "where" — for the full step-by-step, see how to apply for an ITIN.
Option 1: Mail it to the IRS
Send Form W-7, your federal tax return, and original or certified-copy ID documents to the IRS's dedicated ITIN Operations address in Austin, Texas (the current address is printed on the Form W-7 instructions — always use the version from the current tax year).
Option 2: A Taxpayer Assistance Center
Book an appointment at a TAC that offers ITIN document review, so your documents are verified in person and never need to be mailed.
Option 3: A Certifying Acceptance Agent
A CAA certifies your documents directly and submits your application to the IRS. This is the only option available if you're applying from outside the U.S. and don't want to mail an original passport internationally, or if you'd rather apply through an online-friendly process.
