Simple explanation

An ITIN application requires careful document handling because the IRS often needs originals or certified copies. Knowing in advance which documents apply to your situation saves weeks of back-and-forth.

Step-by-step preparation

1. 1

   Confirm you actually need an ITIN

   An ITIN is for people with US tax obligations who are not eligible for an SSN.

2. 2

   Identify your primary identification document

   A valid, unexpired passport is the most common primary ID — it can stand alone. Otherwise, you'll need a combination of two or more other supporting documents.

3. 3

   Gather supporting documents based on your situation

   These can include national IDs, foreign driver's licenses, civil birth certificates, visas, USCIS photo IDs, or school/medical records (for dependents).

4. 4

   Prepare any tax-related supporting documents

   Depending on your reason for applying, you may attach a federal tax return or specific documents proving the requirement (e.g. treaty benefits).

5. 5

   Review the official IRS Form W-7

   Get the current version directly from IRS.gov and read its instructions carefully — they explain exactly which documents apply.

Checklist

Helpful references

• IRS Form W-7 (official application)

  The official form and instructions are on IRS.gov. We do not provide or recreate the form.

• An IRS-authorized Certifying Acceptance Agent (CAA)

  Optional. CAAs can certify documents so you don't need to mail original IDs.

• A document folder

  Keep originals and copies organized and clearly labeled.

Summary

• •A valid, unexpired passport is the simplest primary ID.
• •Otherwise, combine two or more supporting documents.
• •Originals or certified copies are typically required by the IRS.
• •Form W-7 is the official IRS application — get it directly from IRS.gov.