The single detail that stops most non-resident founders from applying for an ITIN is the instruction to send original identity documents to the IRS by mail. Handing your only passport to an international postal system for weeks, with no tracking once it reaches an IRS processing centre, is a reasonable thing to be nervous about. It is also not the only option. This article covers the two realistic ways to get an ITIN without putting your passport in an envelope, what each actually involves, and where the process still has genuine friction you should plan around. You can apply for an ITIN without mailing your original passport to the IRS, and the two safer routes are set out below.
Why founders apply for an ITIN in the first place
An Individual Taxpayer Identification Number is a nine-digit number the IRS issues to individuals who need a US taxpayer identification number but do not qualify for a Social Security Number. For LLC founders, the trigger is usually one of: needing to file a US tax return as a non-resident with US-sourced income, needing an ITIN for a specific withholding form such as a W-8BEN in a situation that requires one, or a platform or partner explicitly requiring one.
It is worth being clear that an ITIN is not the same requirement as an EIN — the EIN identifies the business, the ITIN identifies you as an individual, and many founders never need an ITIN at all if their only requirement is opening a business bank account, which typically runs through the EIN instead. If you are not sure which one your situation actually calls for, our comparison of EIN or ITIN: which one a foreign founder actually needs is worth reading before you start an ITIN application you may not need.
The default process, and why it worries people
The standard route is Form W-7 submitted with original identity documents — most commonly a passport — by mail to the IRS's Austin, Texas processing centre. The IRS returns original documents by mail after processing, typically within 60 days, but "typically" has stretched considerably longer during backlogs, and a passport sitting in transit or in a processing queue for two months is not a small ask for someone who may need it for other travel or business in the meantime. This is the reason the two alternatives below exist and are worth using instead wherever you can.
Route one: a Certifying Acceptance Agent
A Certifying Acceptance Agent, or CAA, is a person or firm authorised by the IRS to review your original identity documents in person (or via a compliant video process, for some agents), verify them, and submit a certified copy to the IRS along with your W-7 — meaning your original passport never leaves your hands. The IRS maintains a public list of authorised CAAs, and a meaningful number operate specifically to serve applicants outside the US, including some who work by video call for non-residents who cannot visit in person.
This is, in nearly all cases, the best option for a non-resident founder. You keep your passport at all times, the CAA verifies the document against the standard the IRS accepts, and the CAA typically bundles submission and follow-up as part of their fee. The trade-off is cost — CAA fees commonly run from $50 to a few hundred dollars depending on the provider and whether the process includes a video verification session — and the need to find a legitimate one, since the field has enough of a paperwork-and-fee model that it attracts a range of quality. Check any CAA against the IRS's published list before paying anyone.
Route two: an IRS Taxpayer Assistance Center
Some IRS Taxpayer Assistance Centers in the US, and a smaller number of facilities at US embassies and consulates abroad, offer document review for ITIN applications, again avoiding the need to mail original documents. The catch is availability: this service exists at a limited set of locations, generally requires an appointment booked in advance, and at overseas posts is offered inconsistently and can be suspended or limited without much notice.
If you happen to be planning travel to the US anyway, or live near one of the consulates that offers this service, it can be a genuinely free alternative to a CAA's fee. If you are not already planning to be near one, the travel cost usually outweighs a CAA's fee for most founders.
Comparing the three routes
| Route | Passport leaves your hands? | Typical cost | Typical turnaround | Availability |
|---|---|---|---|---|
| Mail original documents | Yes, by post | Postage only | ~60 days, longer in backlogs | Always available |
| Certifying Acceptance Agent | No | $50–a few hundred dollars | Similar IRS processing time once submitted | Widely available, including by video for many countries |
| IRS Taxpayer Assistance Center / consulate | No | Usually free | Similar IRS processing time once submitted | Limited locations, appointment required |
What a CAA actually checks and submits
A properly authorised CAA reviews your passport (or other accepted identity document) against the IRS's authentication standard, confirms it is valid and unaltered, makes a certified copy, and completes a Certificate of Accuracy that accompanies your W-7 to the IRS. They cannot guarantee approval — that decision remains entirely with the IRS — but a competent CAA substantially reduces the risk of rejection for a documentation reason, since verifying the document correctly is exactly the part of the process most likely to go wrong when done without experience. Some CAAs also assist with attaching the correct supporting tax return or exception documentation your W-7 needs, which is a separate common source of rejection covered in more detail below.
What still requires care even with a CAA
Using a CAA avoids the passport-by-mail problem, but it does not remove every other way a W-7 application can be rejected. You generally still need a valid reason for applying — most non-exception ITIN applications must be submitted together with the US tax return that creates the need for the number, not as a standalone request. If you are applying under one of the specific exceptions to that rule (certain treaty-based withholding situations, for example), the exception documentation has to be correct and attached, and getting this wrong is one of the more common rejection reasons regardless of which document-verification route you used.
Timeline planning
Because ITIN processing time is similar regardless of which document-verification route you take, the main thing a CAA or Taxpayer Assistance Center saves you is the passport-in-transit risk and the associated stress, not weeks of processing time. Build in the same 7–11 week runway (the IRS's own typical estimate, longer in peak season around the April filing deadline) regardless of route, and avoid applying for the first time right before the peak season if your timeline has any flexibility at all, since that is when both processing times and CAA appointment availability are at their worst.
If your ITIN is needed to support a specific deadline — a treaty withholding claim, a return due date, or a partner's onboarding requirement — tell your CAA that deadline explicitly when you engage them. A good CAA can sometimes flag realistic risk to your timeline early, before you have committed to a date you cannot actually meet, whereas applying by mail on your own gives you no such early warning if something in the package is likely to cause delay.
What to do if your ITIN application is rejected
Rejections typically cite one of a short list of reasons: missing or incorrect supporting tax documentation, an identity document that does not meet the IRS's authentication standard, or an incomplete W-7 field. A CAA reduces the odds of the second cause specifically but cannot fix an incorrect reason for applying or a missing return. If you are rejected, the IRS notice will state a reason — address that reason specifically and resubmit rather than repeating the same package, since resubmitting an uncorrected application simply produces the same rejection again.
How this fits into the wider paperwork sequence
For most founders forming a US LLC from outside the country, the ITIN is not the first document you need — it usually comes after the LLC is formed and after the EIN is issued, if it is needed at all. A typical sequence runs: form the LLC, obtain the EIN (see our guide on getting an EIN as a non-resident with no SSN if you have not done this step), open a business bank account using the EIN, and only then work out whether a specific tax filing situation requires you personally to hold an ITIN as well.
Applying for an ITIN before you actually have a concrete reason to — a tax return to attach it to, or a specific exception that applies to you — is a common way applications end up rejected for lacking supporting documentation, since the IRS generally will not issue one speculatively.
It is also worth checking your underlying tax position before assuming you need an ITIN at all. Our overview of whether non-resident LLC owners owe US tax covers the situations that typically create a personal filing obligation in the first place, since that obligation — not the LLC's existence on its own — is usually what makes an ITIN necessary.
Choosing a CAA without getting burned
Because the CAA market includes everyone from specialised immigration and tax firms to loosely affiliated intermediaries, a few checks are worth doing before you pay anyone:
- Confirm the individual or firm's name appears on the IRS's own published Acceptance Agent list for your country or for remote service, rather than relying solely on the provider's own website claim.
- Ask directly whether the fee includes preparing the W-7 itself and any required supporting tax documentation, or only the identity verification step, since these are sometimes priced and marketed separately.
- Ask what happens, contractually, if the IRS rejects the application — whether resubmission support is included in the original fee or billed again.
- Be wary of any provider that asks you to send a photo of your passport over an unencrypted channel such as ordinary email, given how sensitive that document is.
What "certified copy" actually means here
A common point of confusion is the difference between a certified copy made by a CAA and a certified copy made by a notary or by the issuing passport authority. For ITIN purposes specifically, the IRS only accepts certification through its own recognised channels — a CAA operating under its IRS agreement, or specific government-issued certified copies in the limited cases the W-7 instructions allow.
A standard notarised photocopy from a local notary public, which is a common and useful document for many other purposes, is generally not accepted for a W-7 unless it falls within those specific IRS-recognised categories. This is one of the more common and avoidable rejection reasons, and it is exactly the kind of detail a genuine CAA is trained to get right on your behalf.
Frequently asked questions
Is a Certifying Acceptance Agent an IRS employee?
No. A CAA is typically an accountant, attorney, or specialised service provider authorised by the IRS to verify identity documents for ITIN purposes, but they are independent of the IRS and charge their own fee for the service. Always confirm a specific CAA's authorisation against the IRS's published list before paying.
Can I complete the CAA process entirely by video call?
Many CAAs who specifically serve applicants outside the US do offer video verification, but not all of them, and requirements can vary by the CAA's own process and by country. Confirm this directly with the specific CAA before assuming it is available, since some still require in-person review.
Do I need an ITIN to open a US business bank account?
No, in most cases. US business bank accounts for a foreign-owned LLC are typically opened using the LLC's EIN, not the owner's ITIN. Many founders never need an ITIN at all unless a specific tax filing or withholding situation calls for one.
How long does an ITIN stay valid once issued?
An ITIN generally remains valid as long as it is used on a federal tax return at least once every three consecutive years. If it goes unused for three consecutive tax years, it expires and needs to be renewed with a fresh W-7 before it can be used again.
If you would rather have this handled for you, our US LLC formation service covers it end to end. For the official position, see IRS ITIN guidance.