ITIN Application (Form W-7): Complete 2026 Guide for Foreign Founders

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	7-11 weeks (longer during filing season Jan-Apr)
Document path	Original passport OR Certified 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 who has NO US source income personally (the entity has no US business yet, or only has foreign income) typically does NOT need an ITIN. The entity needs an EIN; the individual does not necessarily need an ITIN.

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 for themselves (if they have US tax obligations), and eventually an SSN if they obtain US work authorization. The ITIN does not "convert" to an SSN, if the founder later gets an SSN, the ITIN is retired.

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)

Mail Form W-7 along with the ORIGINAL passport (or a certified copy from the issuing agency, not from a notary) to the IRS ITIN Operation in Austin, TX. The IRS holds the document for 7-11 weeks, then returns it via mail.

Risk: the original passport is in the IRS's possession for 2-3 months. Most foreign founders cannot afford to be without their passport for this long. This path is rarely practical.

Cost: $0 if you do the application yourself. International postage may add modest cost.

Path 2: Certified Acceptance Agent (CAA), Recommended

A Certified 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: 7-11 weeks once the CAA submits the W-7. The CAA can confirm submission and track status.

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 TACs offer ITIN service, and appointments are required (call +1-844-545-5640). Many TACs have multi-week waiting lists.

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: separate W-7 applications are required for each dependent, with their own supporting documentation.

ITIN Renewal and Expiration

ITINs expire after 3 consecutive years of non-use on a US tax return. If an ITIN holder does not file (or be claimed as a dependent on) a US return for 3 consecutive years, the ITIN expires.

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.

Common ITIN Application Mistakes

Mistake 1: Submitting notarized copies instead of certified copies. Notaries cannot certify the authenticity of foreign government IDs. The IRS will reject the application. Use original documents or certified copies from the issuing agency only.

Mistake 2: Submitting W-7 without a tax return or qualifying exception documentation. The IRS will reject the application as not demonstrating a tax filing requirement.

Mistake 3: Using the passport submission path and being without a passport for 3 months. Use a CAA instead.

Mistake 4: Not knowing the ITIN expired. ITINs expire after 3 years of non-use. If the entity has not had US tax filing activity, the ITIN may need renewal.

Mistake 5: Confusing ITIN with EIN. The entity needs an EIN (immediate, free, online for US founders). The individual may also need an ITIN (separate application, slower, may require a CAA for foreign founders).

How File.Business Handles ITIN Applications

File.Business partners with IRS Certified 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 Certified 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 Certified Acceptance Agents to handle ITIN applications without requiring you to mail your original passport. Standalone service: $349 flat including CAA verification fee.