Two things make ITIN applications go wrong more often than they should. Many people apply who do not need one, having confused the individual number with the entity number. And the documentation rule is unusually strict: originals or agency-certified copies only, so a notarised copy that satisfies almost any other institution is refused here. Get both right and the rest is a waiting time.
What an ITIN Actually Is
An Individual Taxpayer Identification Number (ITIN) is a nine-digit tax identification number issued by the IRS to individuals who are not eligible for a Social Security Number but who have a US tax filing requirement. The format is the same as an SSN (XXX-XX-XXXX) but always begins with the digit 9.
The ITIN is for INDIVIDUALS, it identifies a person to the IRS, not an entity. The entity-level equivalent is the EIN (covered separately in this series). Foreign founders often confuse the two: the entity needs an EIN; the individual founder may also need an ITIN if they have personal US tax obligations.
The ITIN is for tax purposes ONLY. It does not authorize work in the US, does not provide immigration status, and does not entitle the holder to Social Security benefits. It exists solely to facilitate federal tax compliance.
Who Needs an ITIN
At a Glance
| Item | Value |
|---|---|
| Form | IRS Form W-7 |
| Cost | $0 (free), CAA fees vary ($150-$400) |
| Processing time | 7 weeks; 9 to 11 weeks from January 15 to April 30 or from overseas |
| Document path | Original passport OR Certifying Acceptance Agent OR IRS Taxpayer Assistance Center |
| Renewal cycle | Expires after 3 consecutive years of non-use |
A foreign founder of a US LLC or corporation needs an ITIN if any of these apply:
(1) The entity has US source income and the individual receives a distribution requiring withholding (Form 1042-S).
(2) The individual must file a US tax return (Form 1040-NR for nonresident aliens, Form 1040 for resident aliens) due to US source income.
(3) The individual is a beneficial owner subject to US backup withholding.
(4) The individual wants to claim a tax treaty benefit (reduced withholding rate on US source income).
A foreign founder of a US LLC with no personal US source income, because the entity has no US business yet or earns only foreign income, typically does not need an ITIN at all. The entity needs an EIN; the individual does not necessarily need anything. Advisers who bundle the two together sell a lot of unnecessary ITIN applications.
Compliance monitoring
If you would rather not do this yourself, we track every deadline for your entity and file on time, in every state where you are registered. Or keep reading and file it on your own. This guide covers everything you need either way.
ITIN vs EIN vs SSN
SSN (Social Security Number): for individuals who are US citizens or authorized to work in the US. Issued by the Social Security Administration. Required for employment, federal benefits, and most personal tax filings.
EIN (Employer Identification Number): for ENTITIES (LLCs, corporations, partnerships, trusts). Issued by the IRS. Required for business bank accounts, payroll, federal tax returns.
ITIN (Individual Taxpayer Identification Number): for INDIVIDUALS who are not eligible for an SSN but have US tax obligations. Issued by the IRS. Used for personal tax filings only.
A foreign founder might need all three over time: an EIN for the entity immediately, an ITIN personally if US tax obligations arise, and eventually a Social Security number with US work authorisation. The ITIN does not convert; when a Social Security number is issued the ITIN is retired and the earlier records are associated with the new number.
Which of the three a payer should be collecting from you, and on which form, is a separate question with its own penalties. A US person gives a Form W-9; a foreign individual gives a W-8 BEN. If the entity behind the individual is a single-member LLC, the payer looks through it to the owner, which is where most of the confusion in this area starts.
How to Apply for an ITIN
The application is filed on Form W-7, accompanied by supporting documentation proving identity and foreign status. There are three primary application paths.
Path 1: Submit Original Passport to the IRS (Slow but Free)
Post Form W-7 with the original passport, or a copy certified by the issuing agency rather than a notary, to Internal Revenue Service, ITIN Operation, P.O. Box 149342, Austin, TX 78714-9342. The IRS holds the document and returns it by post. Allow 7 weeks for a decision, or 9 to 11 weeks if filed between January 15 and April 30 or sent from outside the United States, plus return post.
Risk: the passport sits with the IRS for two to three months. Most people who travel for work cannot be without it that long, which is why the free route is rarely the right one. Include prepaid express postage for the return leg if you use it.
Cost: $0 if you do the application yourself. International postage may add modest cost.
Path 2: Certifying Acceptance Agent (CAA), Recommended
A Certifying Acceptance Agent is an individual or organization authorized by the IRS to verify identity and foreign status documents on behalf of ITIN applicants. The CAA reviews your original passport in person (or via secure video session for some CAAs), submits Form W-7 with a Certificate of Accuracy, and you keep your original passport throughout.
CAAs are spread across the US and many countries. The IRS publishes a list of CAAs on its website by country. Many CPA firms and immigration attorneys are CAAs.
Cost: CAA fees typically range $150-$400 depending on complexity and location. The IRS itself does not charge a fee.
Processing time: the same queue, 7 weeks normally and 9 to 11 weeks in the January 15 to April 30 window or from overseas. A CAA changes the document risk, not the wait, and can confirm submission and follow up.
Path 3: IRS Taxpayer Assistance Center (TAC)
Some IRS Taxpayer Assistance Centers (TACs) accept ITIN applications in person. The TAC employee verifies the passport on the spot and returns it immediately. The W-7 is submitted to the IRS by the TAC.
Availability: limited. Only certain Taxpayer Assistance Centers handle ITIN documentation, all visits are by appointment, and the appointment line is +1-844-545-5640. Waiting lists of several weeks are common, so book before you need it rather than after.
This path is most useful for foreign founders who are physically in the US and can travel to a TAC.
When to Submit Form W-7
Form W-7 is submitted WITH a federal tax return, in most cases. This is the IRS rule: an ITIN application must demonstrate a tax filing requirement.
Exception 1: tax treaty benefit. If applying solely to claim a tax treaty benefit on US source income, attach the documentation showing the treaty position (e.g., Form W-8 BEN with the treaty claim) instead of a tax return.
Exception 2: third-party withholding. If the applicant is subject to withholding by a US payor (interest, royalties, dividends), the W-7 can be submitted with documentation of the withholding obligation.
Exception 3: backup withholding. If subject to US backup withholding under specific scenarios.
For most foreign founders, the W-7 is submitted with the first US tax return (typically Form 1040-NR for nonresident aliens).
Supporting Documents Required
The Form W-7 must be accompanied by ONE of: (a) original passport (the only single document that proves both identity AND foreign status); (b) two of: national ID card, US driver's license, foreign driver's license, US state ID card, visa, US military ID, foreign military ID, civil birth certificate (for dependents under 14), medical records (under 6), or school records (under 18).
In all cases the documents must be either ORIGINALS or certified copies issued by the issuing agency. Notarized copies are NOT accepted. Photocopies are NOT accepted.
For CAA submissions: the CAA verifies the originals in person and issues a Certificate of Accuracy, the originals are NOT sent to the IRS.
For dependents claimed on a US tax return: each needs their own Form W-7 and documentation. Expect the calendars to collide, since this peaks in the same weeks as federal entity returns and 1099 reporting.
ITIN Renewal and Expiration
An ITIN that was not included on at least one US federal tax return for the last three consecutive tax years expires on 31 December of that third year and must be renewed before it is used again. The clock runs on use, not on age, so an ITIN obtained in 2020 and used every year since is still current, while one obtained in 2024 and unused since is not.
To renew an expired ITIN: submit Form W-7 with "Renewal" indicated and supporting documents. Same paths as initial application (passport, CAA, or TAC).
The IRS periodically retires ITIN ranges (e.g., ITINs with certain middle digits). Affected taxpayers are notified by mail. Renewal is required even if the ITIN was used recently.
Three ITIN Applications in Practice
The three below are composites. The IRS processing times, addresses and withholding rates are real; the personal facts are illustrative.
Example 1: Beatriz Salgado files a return and the W-7 together
A Guadalajara consultant owns a US single-member LLC that earned $84,000 effectively connected with a US trade or business in 2026. That gives her a Form 1040-NR to file and no Social Security number to file it with. The W-7 goes in attached to the return rather than on its own, and the package is posted to the ITIN Operation address in Austin rather than the usual individual return address. She files in June rather than March, because the January to April window is where the queue stretches from 7 weeks to 11. The LLC's own obligations run in parallel; see Form 5472 and forming a US LLC without an SSN.
Example 2: Anand Iyer and $18,000 of withheld royalties
A software author in India licenses a product to a US publisher for $60,000 a year. Without documentation the publisher must withhold 30%, which is $18,000. With a valid W-8 BEN claiming the treaty rate, the withholding falls. The obstacle is that a treaty claim on the W-8 BEN needs a US taxpayer identification number, and he does not have one. His W-7 therefore goes in under a treaty exception with the signed licence agreement and a letter from the publisher, rather than with a tax return. Until it is issued, the publisher is right to withhold at 30%, and every quarter that passes is another $4,500 held back that only a filed return will recover. Which form the publisher should be collecting is set out in W-9 versus W-8 BEN.
Example 3: Klara Weiss discovers an expired number
An Austrian designer obtained an ITIN in 2021, then had no US filing obligation for 2022, 2023 or 2024. Her number expired on 31 December 2024 under the three consecutive year rule and nobody told her. She learns of it in 2026 when a return filed with the expired number is processed without the credits claimed on it. The renewal is the same Form W-7 with the renewal box marked, the same documentation standard, and the same seven weeks she did not have. Anyone holding an ITIN through a quiet few years should check the date before the filing season, not during it.
Common ITIN Application Mistakes
Five failures account for most rejected W-7 applications. Each costs the full processing time again.
Mistake 1: Sending notarised copies instead of certified ones
What happens. The applicant has a local notary certify a photocopy of the passport and posts that. Why it fails. The IRS accepts originals, or copies certified by the agency that issued the document. A notary attests to a signature, not to the authenticity of a foreign government identity document. Consequence. Rejection, the documents returned, and another seven to eleven weeks from the day a compliant package goes back. Prevention. Use the issuing agency's certified copy, or use a Certifying Acceptance Agent and keep the original in your hand.
Mistake 2: Filing the W-7 with nothing attached
What happens. The form is posted on its own, on the view that the number is needed before anything else can happen. Why it fails. An ITIN is issued to someone with a demonstrated federal tax purpose. The W-7 travels with the return, or with documentation supporting one of the exceptions. Consequence. Rejection for not establishing a filing requirement, with the same time cost. Prevention. Decide first which reason applies, tick the matching box on the form, and attach the evidence for it.
Mistake 3: Posting the passport when you need to travel
What happens. The applicant takes the free route and sends the original document. Why it fails. Nothing fails procedurally; the passport is out of reach for two to three months. Consequence. Cancelled travel, or a request to have it returned that restarts the application. Prevention. Use a Certifying Acceptance Agent or a Taxpayer Assistance Center appointment if you will need it.
Mistake 4: Filing with a number that expired quietly
What happens. A return is filed with an ITIN that has not appeared on a return for three consecutive years. Why it fails. The number expired on 31 December of that third year. The return is processed, but claims that depend on a valid ITIN are not allowed. Consequence. A notice, a reduced refund or an increased balance, and a renewal that takes the same seven weeks. Prevention. Check the last year the number appeared on a return before the filing season starts.
Mistake 5: Applying for an ITIN when the EIN was the answer
What happens. A founder outside the US is told to get an ITIN before the company can get its federal number. Why it fails. They are different numbers for different taxpayers. An entity gets an EIN, and a responsible party with no Social Security number or ITIN enters FOREIGN on line 7b of Form SS-4. Consequence. Months lost on an application that was never on the critical path. Prevention. Ask what the number is for. If the answer is the company, it is an EIN.
What Happens While You Wait, and What It Costs
The ITIN itself carries no penalty and no fee. The exposure is in what cannot happen until it exists, and in most cases that is money held back rather than money charged.
A treaty claim on Form W-8 BEN is invalid without a US taxpayer identification number, so the payer withholds at the statutory 30% on US source fixed or determinable income. On $60,000 of annual royalties that is $18,000 withheld instead of the treaty amount, recoverable only by filing a US return afterwards. On $200,000 it is $60,000.
A US person who never returns a Form W-9 faces backup withholding at 24% instead. Getting the wrong form from a payee produces the wrong withholding in both directions.
And the queue is itself a cost. Seven weeks is the published figure outside the January 15 to April 30 window, 9 to 11 weeks inside it or from overseas. An application posted in February to support a treaty claim on a March contract will not arrive in time, and the payer will withhold at 30% in the meantime. Applying in the autumn for the following year is the cheapest scheduling decision here. CAA fees of $150 to $400 buy document safety, not speed.
How File.Business Handles ITIN Applications
File.Business partners with IRS Certifying Acceptance Agents to handle ITIN applications for foreign founders. Service includes: confirming whether an ITIN is actually needed (many foreign founders do not need one); preparing Form W-7 with the correct application category and exception code; coordinating the CAA passport verification (in person or via secure video session); submitting the W-7 to the IRS with the Certificate of Accuracy; tracking status and following up on any IRS correspondence; delivering the ITIN assignment letter to your document vault.
Standalone ITIN service: $349 flat (includes CAA verification fee). Renewals: $199 flat. We confirm necessity first, many foreign founders are advised to apply for an ITIN when they don't actually need one for their current situation.
Frequently Asked Questions
Do I need an ITIN as a foreign founder of a US LLC?
Not always. You need an ITIN if you have personal US tax obligations (US source income, treaty benefit claim, US backup withholding). If your LLC has no US business yet, you typically do not need an ITIN. The entity still needs an EIN.
How long does ITIN processing take?
7-11 weeks once the W-7 is submitted to the IRS, longer during peak filing season (January through April). The wait is in the IRS processing queue, not in the application preparation.
Can I keep my passport during the ITIN application?
Yes, if you use a Certifying Acceptance Agent (CAA) or an IRS Taxpayer Assistance Center. The CAA verifies your passport and submits a Certificate of Accuracy instead of the original. Avoid the direct passport submission path unless you can be without your passport for 2-3 months.
What is the difference between ITIN and EIN?
ITIN is for INDIVIDUALS who are not eligible for an SSN but have US tax obligations. EIN is for ENTITIES (LLCs, corporations). They are different numbers issued for different purposes. A foreign founder may need both.
Does the ITIN authorize me to work in the US?
No. The ITIN is for tax purposes only. It does not authorize work, provide immigration status, or entitle the holder to Social Security benefits. US work authorization requires separate immigration processes.
Does my ITIN expire?
Yes. ITINs expire after 3 consecutive years of non-use on a US tax return. If the ITIN holder has not filed (or been claimed as a dependent on) a return for 3 years, renewal is required.
Can File.Business get me an ITIN?
Yes. File.Business partners with IRS Certifying Acceptance Agents to handle ITIN applications without requiring you to mail your original passport. Standalone service: $349 flat including CAA verification fee.
File.Business handles federal compliance for you
From EIN to Form 5472, federal filings stack up fast. File.Business pairs your entity with the right federal filings on a single calendar, with deadline tracking, automatic preparation, and CPA partnership for income tax returns.
This guide is written from the official sources below. Fees, forms, and deadlines change; confirm the current requirement with the agency before you file.
Disclosure. File.Business is a private filing service, not a government agency and not a law firm. We prepare and submit filings at your direction, and nothing on this page is legal or tax advice. Filing fees, deadlines, and statutory references are current as of the last-updated date shown above and can change. Confirm current requirements with the relevant state agency before you file.
