ITIN Application by Mail: Step-by-Step Guide 2026

Step 1: Prepare Your Documents

Before assembling your mailing package, gather all required documents. Missing even one item can result in your application being returned or delayed by weeks.

Required Items

• Completed Form W-7: Download from IRS.gov. Complete all applicable fields. Sign and date the form. If applying for a dependent, the primary taxpayer signs.
• Federal tax return: Form 1040, 1040-NR, or other applicable return. The W-7 is attached to the front of the tax return. If you qualify for an exception, include the exception documentation instead.
• Identification documents: Original passport (standalone) or two documents from the 13 accepted documents list. Must be originals or certified copies from the issuing agency.

Optional but Recommended

• Cover letter listing all enclosed documents with a return address
• Copies of everything for your personal records (make copies before mailing)
• Prepaid return envelope if you want your documents returned to a specific address

Step 2: Complete Form W-7 Correctly

Form W-7 is a 2-page form with 6 sections. The most common errors that cause rejection are incorrect name spelling, wrong box selection in the reason for applying section, missing signature, and inconsistencies between the W-7 and the attached tax return.

• Line 1a-1b: Enter your name exactly as it appears on your passport or primary identification document. If your name has changed, check box 1b and provide your previous name.
• Line 2: Enter your complete mailing address where the IRS will send your CP565 notice. Double-check this address because errors mean your ITIN notification goes to the wrong location.
• Line 3: Enter your foreign address if different from your mailing address.
• Line 4: Enter your date of birth in MM/DD/YYYY format.
• Line 5: Enter your country of citizenship.
• Line 6a: Check the box for your reason for applying. Most applicants check box (a) for nonresident alien filing a tax return, box (b) for resident alien filing a tax return, or box (d) for dependent of a US citizen or resident.
• Signature: Sign and date the form. For dependent applications, the primary taxpayer signs. The signature must be original (not a photocopy).

Step 3: Assemble Your Mailing Package

Organize your documents in this order from top to bottom.

1. Cover letter (optional but recommended)
2. Completed Form W-7 (on top of the tax return)
3. Federal tax return (Form 1040, 1040-NR, etc.)
4. Identification documents (passport, national ID, etc.)
5. Any supporting documentation for exceptions

Use a sturdy envelope or padded mailer large enough to hold all documents without folding. Do not staple your passport or other original documents. Use paper clips or binder clips to keep documents organized. Place documents in a clear plastic sleeve inside the envelope for protection against moisture.

Step 4: Mail Your Application

The IRS ITIN mailing address depends on your shipping method.

Recommended Mailing Methods

Step 5: Wait for Processing and Check Status

After mailing your application, the IRS processing timeline begins. Here is what to expect at each stage.

1. Mail transit (3 to 14 days): Track your package using the shipping receipt. Confirm delivery before moving to the waiting phase.
2. IRS intake (2 to 5 days): The IRS mailroom opens, sorts, and enters your application into the processing system. No notification is sent.
3. IRS processing (6 to 11 weeks): Your application is reviewed, documents verified, and ITIN assigned. No online tracking is available.
4. Call for status after 7 weeks: Call 1-800-829-1040 and say "ITIN" when prompted. Have your name, mailing address, and submission date ready.
5. Receive CP565 notice (1 to 2 weeks after processing): The IRS mails your ITIN notification letter and returns your original documents (if applicable) separately.

7 Common ITIN Mail Application Mistakes

Avoid these errors that cause delays or rejection of mailed ITIN applications.

1. Forgetting to attach the tax return. The W-7 must be accompanied by a federal tax return unless an exception applies. This is the number one reason for rejection.
2. Mailing to the wrong address. Only the Austin, TX address processes ITIN applications. Applications sent to other IRS offices are redirected, adding weeks to your timeline.
3. Using regular mail without tracking. Without a tracking number, you cannot confirm delivery. If the package is lost, you have no proof of submission.
4. Sending uncertified photocopies. The IRS only accepts originals or copies certified by the issuing agency. Notarized copies and regular photocopies are rejected.
5. Missing signature on Form W-7. An unsigned W-7 is automatically returned. Double-check that the form is signed and dated before sealing the envelope.
6. Name mismatch between W-7 and tax return. Your name must be spelled identically on Form W-7 and the attached tax return. Even minor differences (e.g., middle name vs middle initial) can trigger a correction request.
7. Not keeping copies. Always make copies of everything you mail. If your application is lost or you need to reference your submission, copies are essential.

Mail Application vs In Person vs CAA: Which Is Best?

For most applicants, using a Certifying Acceptance Agent provides the best balance of convenience, safety, and reliability. For applicants in the US near an IRS TAC office, applying in person is also a strong option. DIY mail applications are the lowest cost but carry the highest risk of errors and document loss.