The IRS requires original identification documents to issue an Individual Taxpayer Identification Number (ITIN), and for most non-U.S. applicants that means mailing a passport overseas. There is a cleaner path: a Certifying Acceptance Agent (CAA) authorized by the IRS can verify your passport in person or remotely and submit the Form W-7 application on your behalf, so the original never leaves your possession.
What an ITIN Is and Why Non-U.S. Persons Need One
An ITIN is a nine-digit tax processing number issued by the IRS to individuals who need to file a U.S. tax return or claim a treaty benefit but do not qualify for a Social Security Number. Typical applicants include non-resident aliens with U.S. rental property, Canadian snowbirds earning U.S. gambling winnings or investment income, foreign partners in U.S. LLCs, spouses of U.S. citizens filing joint returns, and non-U.S. dependents claimed on a U.S. return.
Without an ITIN, the IRS withholds at 30% on most U.S. source income even when treaty rates would reduce that to 10%, 15%, or zero. Applying for an ITIN early can unlock treaty-reduced withholding and enable refund claims that would otherwise be stranded.
The Default Path: Mailing Your Passport
Form W-7 filed directly with the IRS requires original passport or a certified copy from the issuing agency. The IRS holds the original for up to 60 days during processing. For most applicants this is impractical: a passport is a primary travel document and most people cannot be without it for two months.
The risk of mailing a passport internationally is also real. Loss, theft, or damage in transit creates weeks of embassy paperwork. Few foreign applicants should use the mail-the-passport path when a Certifying Acceptance Agent is available.
The Certifying Acceptance Agent (CAA) Path
A CAA is an IRS-authorized individual or entity permitted to verify ITIN applicants' identification documents and submit Form W-7 packages with a Certificate of Accuracy. The CAA examines the original passport in person (or via approved remote procedure for certain cases), certifies its authenticity, and returns it immediately to the applicant.
Using a CAA shortens processing because the IRS does not need to verify the underlying document itself, and it eliminates the document-mailing risk entirely. CAAs are also useful for dependents and spouses, where certifying acceptance is specifically authorized under current procedures.
TYM's CAA Process Step by Step
Step 1: We confirm eligibility and purpose (tax return attached, treaty claim, U.S. ownership interest, dependent of U.S. taxpayer). Step 2: We prepare Form W-7 with the correct category code and supporting schedule.
Step 3: The applicant appears for a CAA meeting (in person at our Toronto or Miami office, or by approved video procedure depending on current IRS guidance). We verify the passport, take the required scans, and complete the Certificate of Accuracy.
Step 4: We submit the W-7 package, the attached tax return (if required), and the Certificate of Accuracy to the IRS ITIN Operations unit. The applicant keeps their passport throughout. Step 5: We track status and respond to any IRS follow-up questions until the ITIN is assigned.
Common ITIN Application Problems We Fix
Wrong category code on Form W-7 is the single most common rejection reason. Applicants also run into problems when the tax return is missing, the name on the passport does not match the tax return, the applicant's address is incomplete, or the signature does not match. A properly prepared CAA submission catches each of these before filing.
Renewals are another source of confusion. ITINs not used on a U.S. return for three consecutive years expire, as do ITINs assigned before certain dates that have been rolled into the renewal program. We check status against IRS expiration schedules and renew when needed.
Timing, Cost, and What to Expect
Current IRS processing time for an ITIN submitted by a CAA runs approximately 7 to 11 weeks during non-peak season and can extend during tax season. TYM's CAA fee for a standard ITIN application including Form W-7 preparation is quoted at engagement; family applications are priced together.
If the ITIN is needed for an imminent U.S. filing deadline, we often pair the application with a 6-month extension to avoid late-filing exposure while the ITIN is assigned.
Special Cases: Canadian Snowbirds, Foreign Investors, and Cross-Border Families
Canadian snowbirds who win at U.S. casinos, earn U.S. rental income, or hold U.S. brokerage accounts often need ITINs to reclaim 30% withholding under the Canada-US tax treaty. TYM's Toronto team handles these applications alongside the 1040-NR and the treaty analysis.
Foreign partners in U.S. LLCs need ITINs for K-1 reporting and withholding purposes. Foreign spouses of U.S. citizens choosing joint filing status need ITINs. Foreign dependents can qualify in limited circumstances. Each category has specific documentation we prepare and submit.
After the ITIN: Keeping It Active and Useful
Once issued, an ITIN should be used on every U.S. tax filing that touches the holder. Consistent use avoids expiration. ITIN holders should also update the IRS if they later become eligible for a Social Security Number (the two numbers cannot coexist on the same return).
We maintain a client ITIN registry so renewals, expirations, and SSN transitions are managed proactively rather than reactively.
Coordinating ITIN With State Tax Filings
Many states accept the ITIN on state non-resident tax returns, but a few require their own taxpayer identification process. California, New York, and Massachusetts all recognize ITINs on state filings. State withholding agents may still apply default high-rate withholding when a Social Security Number is not provided, even with an ITIN on file. We coordinate state-level documentation so withholding is calibrated correctly.
For non-residents earning passive U.S. investment income through brokerage accounts, the brokerage's W-8BEN process drives the actual withholding. The ITIN supports the W-8BEN treaty claim, but the brokerage must apply the reduced rate. We help clients refresh W-8BEN forms and submit corrected withholding documents when needed.
Frequently Confused Categories on the W-7
The W-7 application has roughly a dozen reason codes and getting the right one matters. Code 'a' is for non-resident filers needing an ITIN to claim a treaty benefit on FDAP income. Code 'b' is for non-resident filing a U.S. return. Code 'h' covers other (with a description). Codes for spouses and dependents have their own rules and supporting documents.
The wrong code is the leading reason ITIN applications get rejected. Our CAA review checks the code against the applicant's facts before submission, eliminating the most common cause of months of delay.
Does a CAA physically keep my passport?
No. The CAA examines the original, certifies it, and returns it immediately. Your passport does not go to the IRS.
Can I do the CAA verification remotely?
Under current IRS rules, CAAs can use approved remote video procedures for many primary applicants. We will confirm eligibility during the scoping call.
Do I still need to file a U.S. tax return?
In most cases, yes. The ITIN is issued to enable a return to be filed. Certain treaty-claim and pass-through entity situations have exceptions.
How long does the ITIN itself last?
ITINs expire if not used on a U.S. return for three consecutive years. Certain ITIN ranges expire on schedule and must be renewed.