Lost Your ITIN Number? How to Look It Up or Reapply With Form W-7

If you’ve lost your ITIN number, you don’t need to apply for a new one. Your nine-digit number still exists in IRS records. The fastest way to find it is to check a prior federal tax return or old IRS correspondence; if that turns up nothing, call the IRS at 800-829-1040 and they can look it up after verifying your identity.¹ Form W-7 only comes into play if your ITIN has expired or can’t be retrieved any other way.

Check Your Own Records First

Before making any calls, look through paperwork you already have. Your ITIN appears at the top of every Form 1040 you’ve filed, in the identification section next to your name.² A saved PDF, a printed copy in a filing cabinet, or a return stored in your tax software account all work.

Then check IRS mail. When the IRS first assigned your ITIN, it sent you Notice CP565 confirming the number.³ Later IRS letters, such as adjustment notices or account statements, also usually print your taxpayer identification number on them. One of those documents is often all it takes.

Call the IRS to Look It Up

If nothing in your records shows the number, call the IRS directly. Domestic callers use 800-829-1040, open 7 a.m. to 7 p.m. local time, Monday through Friday.⁴ From outside the United States, the number is 267-941-1000, which is not toll-free.¹

Expect a verification process. The agent will ask about your personal history and prior filings before releasing any account information. Hold times run longest during filing season; calling early in the morning, or later in the week, generally moves faster.

Is It Lost, or Actually Expired?

Before you file anything, confirm your ITIN is still active. Many people who think their number is lost actually have an expired one. An ITIN that hasn’t appeared on a federal tax return for any three consecutive tax years expires automatically on December 31 of the third year.⁵ Skip filing for 2022, 2023, and 2024, and the number expired at the end of 2025.

There’s also an older phase-out based on the middle two digits of the ITIN (the fourth and fifth digits in the 9XX-XX-XXXX format). All ITINs with middle digits 70 through 88 have already expired. ITINs with middle digits 90, 91, 92, 94, 95, 96, 97, 98, or 99 expired as well if they were assigned before 2013 and never renewed.

Filing with an expired ITIN causes real problems. The IRS may delay your return, and you can lose eligibility for certain tax credits until the number is renewed, which can shrink a refund or trigger penalties and interest.⁵

When You Need Form W-7

If your ITIN has expired, or you’ve exhausted the record-check and phone options, submit Form W-7 to renew or reactivate it. Check the “Renew an existing ITIN” box at the top of the form, then select the reason box that matches your situation, such as U.S. resident alien filing a federal tax return, or dependent of a U.S. citizen or resident alien.⁶

One requirement catches many applicants: you generally must attach a federal tax return to the W-7. The IRS won’t process the application without one unless you qualify for a narrow exception, such as passive income subject to withholding or tax treaty benefits on certain income types.⁶ If you’re not planning to include the ITIN on a return, the IRS says you don’t need to renew right now.⁵

Renewing for family members listed on the same return? Attach all of their Forms W-7 to that single tax return and the IRS will process them together.⁶

Documents You’ll Need

The W-7 asks for your full legal name, current mailing address, date of birth, and city and country of birth. Spelling has to match your supporting documents exactly. A birthplace spelled one way on the form and another way on your passport is a common reason applications get rejected.

You also need original identification or certified copies from the issuing agency. A valid passport is the simplest option because it proves both identity and foreign status on its own. For dependents, though, a passport without a U.S. entry date stamp doesn’t prove U.S. residency, so an additional document such as a school record, medical record, or state ID is required depending on age.⁷

Without a passport, you submit two documents: one proving identity and one proving foreign status, with at least one showing a photo. National identification cards, birth certificates, foreign voter registration cards, U.S. visas, USCIS photo IDs, and foreign military IDs are among the accepted options.⁷

Three Ways to Submit

How you send in Form W-7 mostly depends on how comfortable you are letting original documents like a passport out of your hands.

Mail to Austin

All ITIN applications go to the IRS processing center in Austin, Texas. You can use the U.S. Postal Service or a private delivery service with tracking.⁸ Delivery confirmation is worth the small extra cost so you can verify the package arrived.

Use a Certifying Acceptance Agent

An IRS-authorized Certifying Acceptance Agent can review your original documents, certify copies, and send the certified copies to the IRS for you. You keep your originals the whole time.⁹ Agents operate both inside and outside the United States. Fees vary widely, often from $50 up to several hundred dollars.

Visit an IRS Taxpayer Assistance Center

You can also have documents verified in person at a designated IRS Taxpayer Assistance Center. An IRS employee reviews your originals and hands them back at the end of the appointment. Appointments are required and can be scheduled at 844-545-5640.¹⁰ This is often the safest choice if you don’t want your passport in the mail for weeks.

How Long Processing Takes

The IRS currently processes Form W-7 applications in about 11 weeks after receipt.¹¹ Peak filing season pushes toward the longer end. When processing finishes, the IRS mails Notice CP565 confirming your ITIN.¹² File it somewhere secure so you don’t end up recovering the number a second time.

If you mailed original documents, the IRS returns them by standard mail. The agency doesn’t publish an exact return window, so watch your mailbox starting a few weeks after submission. If several months pass with no documents, call the IRS to follow up.

One planning point around deadlines: if your ITIN renewal is still in process when your return is due, file on time anyway. The IRS will process the return once the ITIN is active, and the on-time filing avoids a separate set of late-filing penalties.

If You Later Get a Social Security Number

One boundary worth knowing while you’re dealing with your ITIN: if you become eligible for a Social Security number, you must stop using the ITIN and use the SSN for all tax purposes. You also need to notify the IRS so it can merge your records under the new number. Skip that step and the IRS may not credit you for wages and withholding reported under the old ITIN, potentially reducing a refund.¹³

To notify the IRS, visit a local office or mail a letter to the IRS in Austin, TX 73301-0057. Include your full name, mailing address, ITIN, a copy of your Social Security card, and a copy of your CP565 notice if you still have it. The IRS will void the ITIN and link prior filings to your SSN.¹³

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Internal Revenue Service. Individual Taxpayer Identification Number (ITIN)
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USAGov. Get an Individual Taxpayer Identification Number (ITIN) to File Your Tax Return
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Internal Revenue Service. Understanding Your CP565 Notice
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USAGov. Contact the IRS for Questions About Your Tax Return
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Internal Revenue Service. How to Renew an ITIN
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Internal Revenue Service. Instructions for Form W-7
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Internal Revenue Service. ITIN Supporting Documents
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Internal Revenue Service. How to Apply for an ITIN
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Internal Revenue Service. ITIN Acceptance Agents
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Internal Revenue Service. IRS Taxpayer Assistance Centers Providing In-Person ITIN Document Review
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Internal Revenue Service. ITIN Documentation Frequently Asked Questions (FAQs)
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Internal Revenue Service. Notice CP565 – Confirmation of Your Individual Taxpayer Identification Number
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Internal Revenue Service. Additional ITIN Information