ITIN: CAA vs Mailing Originals vs IRS TAC (2026)

TL;DR

• An ITIN is an IRS number for people who need a US taxpayer identification number but can't get a Social Security number (SSN). You apply on Form W-7, normally attached to a federal tax return, unless an exception applies.
• Three ways to have your documents checked: mail the originals to the IRS, use a Certifying Acceptance Agent (CAA), or book a designated IRS Taxpayer Assistance Center (TAC).
• A passport is the only stand-alone document. Without one, you need at least two documents from the IRS list of 13, one with a photo.
• For you and your spouse, a CAA can authenticate every listed document except foreign military ID cards. For dependents, only the passport and civil birth certificate; anything else goes to the IRS.
• The IRS allows the CAA interview by video, but the CAA must physically hold your original documents (or certified copies) during it. Documents can't be authenticated over a camera.
• The IRS publishes one processing timeline: allow 7 weeks, or 9–11 weeks from January 15 to April 30 or if you apply from overseas.
• Since tax year 2025, the Child Tax Credit requires SSNs. An ITIN doesn't qualify.

Three routes compared

Who needs an ITIN

Under the Instructions for Form W-7 (Rev. 12/2024), you apply if you must provide a US taxpayer number or file a federal return but aren't eligible for an SSN. Typical cases:

• a nonresident alien filing Form 1040-NR or claiming a treaty benefit;
• a nonresident spouse electing a joint return with a US citizen or resident;
• a resident alien under the substantial presence test who can't get an SSN;
• a spouse or dependent claimed for an allowable tax benefit, such as a joint return, head of household, the child and dependent care credit or the credit for other dependents.

If you're eligible for an SSN, or your SSN application is pending, don't file Form W-7.

Form W-7: with a return or under an exception

A first-time application includes Form W-7 attached to the front of the original tax return (SSN space left blank) plus your identity documents. Mail it to the ITIN address, not the regular return address.

If you don't need to file a return yet, an exception may apply: passive income with withholding or treaty benefits (Exception 1), certain wages, scholarships and gambling winnings (Exception 2), US mortgage interest (Exception 3), sales of US real property by a foreign person (Exception 4), or T.D. 9363 (Exception 5). You attach the required documents instead of a return.

For foreign founders: from June 1, 2026, a CAA filing under Exception 1(a) (partnership) must include the part of the partnership or LLC agreement showing the partnership's name and EIN and your name and signature.

File the W-7 with the return by its due date, including extensions. You can't e-file a return using an ITIN in the calendar year the ITIN is issued.

Which documents you need

• Originals or certified copies from the issuing agency, not expired. Ordinary photocopies don't qualify.
• Passport: proves identity and foreign status alone. For a dependent who must prove US residency, it stands alone only if it shows a US date of entry (narrow exceptions for military families overseas and some dependents from Canada or Mexico).
• No passport: at least two documents from the list of 13 (national ID card, US visa, foreign driver's license, civil birth certificate and others). One needs a photo unless the dependent is under 14 (under 18 if a student). Applicants under 18 without a passport need an original civil birth certificate.
• Dependents' US residency: medical records (under 6), school records (under 24 if a student), a US state ID, driver's license or visa; from age 18, also a US bank statement, rental statement or utility bill.

What a CAA can and can't do

The IRS ITIN Acceptance Agent Program page (updated April 30, 2026) sets the rules:

1. Primary applicant and spouse: a CAA can authenticate all identification documents except foreign military ID cards, which go directly to the IRS.
2. Dependents: a CAA can authenticate the passport and civil birth certificate; all other dependent documents must be sent to the IRS.
3. Certificate of Accuracy: the CAA attaches Form W-7 (COA) to each W-7, showing which documents it reviewed. The IRS isn't bound by it and may still ask for documents.

In person or by video? The same IRS page requires acceptance agents to conduct an in-person interview with every applicant (primary, secondary and dependent) and adds that video conferencing may be used for the interview only. Even then, the CAA must have the original documents, or certified copies from the issuing agency, in its possession during the interview. Publication 4520 explains why: the agent must see the security features to authenticate them. The conversation can happen on video; the passport check cannot.

If you live abroad and a US-based agent completes your W-7 during a visit to the US, IRS Form 15003 (Rev. 1-2017) requires an attestation that you were interviewed in person at a US location, not by video.

A non-certifying Acceptance Agent (AA) helps with the form but sends originals for every applicant to the IRS. A CAA also receives copies of your ITIN notices and can work with the IRS on problems. More about our service: ITIN through a CAA.

The TAC and mail routes

TAC. Designated TACs verify originals and return them at the end of the appointment; for dependents they verify passports, national ID cards and birth certificates. Appointments only (844-545-5640), and the IRS warns they may take several weeks to get. Abroad, US embassies and consulates may certify copies.

Mail. Internal Revenue Service, ITIN Operation, P.O. Box 149342, Austin, TX 78714-9342. Originals come back to the address on line 2 within 60 days; you may include a prepaid courier envelope. If you need your passport sooner, the IRS itself points to a TAC or a CAA.

Processing time

Allow 7 weeks for the IRS to notify you, or 9–11 weeks during peak season (January 15 – April 30) or if you apply from overseas. The IRS publishes one timeline for all routes: a CAA saves you from mailing your passport, not from the IRS queue.

ITIN expiration

Under IRC §6109(i)(3)(A), an ITIN issued after 2012 stays in effect unless it isn't used on a federal return (including as a dependent on someone else's return) for 3 consecutive tax years. The statute says it then expires the day after that third year's return due date; the IRS says December 31 of the third year. Renew with Form W-7 and the return on which you'll use the ITIN. Filing with an expired ITIN can delay processing.

The 2025 change: Child Tax Credit needs SSNs

P.L. 119-21, signed July 4, 2025, rewrote IRC §24(h)(7) for tax years beginning after December 31, 2024. No Child Tax Credit is allowed unless the return shows the taxpayer's SSN (on a joint return, at least one spouse's) and the child's SSN, each valid for employment (or issued to a US citizen) and issued before the return's due date. Under IRC §24(h)(4)(C), a child who fails only this test is treated as a dependent for the $500 credit for other dependents, which may still apply if the child is a US citizen, national or resident. Per the W-7 instructions, ITIN filers also can't claim the earned income credit.

How to choose

• Don't want your passport to go to the IRS: a CAA (in person, or by courier for the interview) or a TAC appointment.
• Abroad: a CAA abroad, an in-person CAA meeting during a US visit, or certified copies; mailing originals is the fallback.
• Dependents with school or medical records: those go to the IRS anyway, so plan for mail or a TAC.

Sources

• IRS — ITIN Acceptance Agent Program
• IRS — ITIN acceptance agents (for applicants)
• IRS — Instructions for Form W-7 (Rev. 12/2024)
• IRS — How to apply for an ITIN
• IRS — ITIN supporting documents
• IRS — Form W-7 (COA)
• IRS — Publication 4520
• IRS — Form 15003
• IRS — How to renew an ITIN
• 26 U.S.C. §6109
• 26 U.S.C. §24

Need help with Form W-7 or an ITIN renewal? Book a consultation.