How Do I Apply for an ITIN?

Ultimate Guide for International Founders in 2026

Starting a business in the U.S. as an international founder comes with unique compliance requirements—and obtaining an Individual Taxpayer Identification Number (ITIN) is often one of the first steps.

If you don’t qualify for a Social Security Number (SSN), an ITIN allows you to meet your U.S. tax obligations and operate smoothly as a founder, investor, or business owner.

Let’s break it down clearly.

What Is an ITIN?

An Individual Taxpayer Identification Number (ITIN) is a tax processing number issued by the Internal Revenue Service (IRS).

The IRS issues ITINs to individuals who:

• Are required to have a U.S. taxpayer identification number
• Do not have an SSN
• Are not eligible to obtain an SSN from the Social Security Administration (SSA)

ITINs are issued regardless of immigration status.

Both resident and non-resident aliens may have U.S. tax filing or reporting obligations under the Internal Revenue Code.

What Is an ITIN Used For?

The IRS issues ITINs to:

• Allow individuals to comply with U.S. tax laws
• Process tax returns and payments
• Report income earned in the U.S.
• Claim tax treaty benefits (where applicable)
• Be listed as a partner, member, or shareholder in a U.S. entity

For international founders, an ITIN is often required if:

• You own a U.S. LLC or corporation
• You receive U.S.-source income
• You must file Form 1040-NR
• You are listed on business tax filings

What an ITIN Does NOT Do

It’s important to understand the limitations.

An ITIN:

• ❌ Does not authorize you to work in the U.S.
• ❌ Does not provide eligibility for Social Security benefits
• ❌ Does not serve as proof of immigration status
• ❌ Does not qualify dependents for Earned Income Tax Credit (EITC)

An ITIN is strictly for federal tax reporting purposes.

ITIN vs SSN (Quick Comparison)

SSN	ITIN
Issued to U.S. citizens & eligible residents	Issued to individuals not eligible for SSN
Required for employment	Does not authorize employment
Used for Social Security benefits	Used only for tax reporting
Serves broader identification purposes	Limited strictly to IRS tax processing

Why ITIN Matters for International Founders in 2026

In 2026, compliance scrutiny for international founders is stronger than ever. An ITIN helps you:

• Stay compliant with U.S. tax laws
• Avoid higher withholding rates
• File personal U.S. tax returns
• Maintain good standing with the IRS
• Support long-term immigration or investment plans

Without an ITIN, tax filings may be delayed, rejected, or subject to higher withholding.

Who Needs to Get an ITIN?

As a foreign national, you generally need to apply for an ITIN (Individual Taxpayer Identification Number) if:

• You have a U.S. federal tax filing requirement (or informational reporting requirement), and
• You do not qualify for a Social Security Number (SSN)
  

In simple terms: if you must file taxes in the U.S. but are not eligible for an SSN, you likely need an ITIN.

This commonly applies to:

• Non-resident founders of U.S. LLCs or corporations
• Foreign partners in U.S. partnerships
• Foreign investors receiving U.S.-source income
• Spouses or dependents of visa holders (who are not SSN-eligible)

ITIN requirements can sometimes be misunderstood, especially among global founders managing cross-border income.

What Is the Difference Between an ITIN, EIN, and SSN?

Although these numbers may seem similar, they serve very different purposes.

Identifier	Purpose	Who Needs It	Use Cases
ITIN	Tax compliance for non-residents and foreigners	Non-residents and foreign nationals without SSNs	Filing personal U.S. taxes, being listed on business filings
EIN	Business tax identification	U.S. and foreign business entities	Paying employees, filing business taxes, opening business bank accounts
SSN	Personal identification and employment	U.S. citizens and eligible residents	Employment, credit applications, personal tax filings

Quick Breakdown

• ITIN → For individuals who need to file U.S. taxes but are not eligible for SSN.
• EIN (Employer Identification Number) → For businesses, issued by the Internal Revenue Service.
• SSN → Issued by the Social Security Administration for employment and personal identification.

If you are an international founder, you may need both an EIN (for your company) and an ITIN (for yourself).

How Do I Get an ITIN?

There are limited exceptions where you can apply without filing a tax return, but in most cases, you must meet the following conditions:

Basic Requirements

• You have a U.S. tax filing requirement, and
• You are required to file a federal income tax return
  

Documents Required for ITIN Application

To apply, you must submit:

1. Form W-7
   (Application for IRS Individual Taxpayer Identification Number)
2. U.S. Federal Income Tax Return
   (Usually attached unless you qualify for an exception)
3. Proof of Foreign Status
   
4. Proof of Identity
   

Proof of Identity & Foreign Status

Your passport is the only document that satisfies both:

• ✔ Proof of identity
• ✔ Proof of foreign status

Because of this, it is the most common and simplest option.

If you do not use a passport, you must submit a combination of other IRS-approved documents that separately establish identity and foreign status.

Important Notes for International Founders

• ITIN applications are submitted to the IRS along with Form W-7.
• Original documents or certified copies are required.
• Errors in Form W-7 often lead to rejection and delays.
• Processing times are longer during peak tax season (January–April).

Applying correctly the first time is critical to avoid delays that can impact business filings and compliance.

Is There an Exception for Getting an ITIN for LLC Owners?

Again, to re-iterate, generally, the ITIN application must accompany your tax return.

However, per the exception 1(a) listed on the IRS site (and image below as well):

📌 People eligible to claim Exception 1(a) include:

Individuals who are partners of a US or foreign partnership that invests in the United States and that owns assets that generate income subject to IRS information-reporting and federal tax withholding requirements.

📌 Documentation you must submit if you’re eligible to claim Exception 1(a):

A copy of the portion of the partnership or LLC agreement displaying the partnership’s employer identification number and showing that you’re a partner in the partnership that’s conducting business in the US.

 

Download now: Exception 1(a) from Form W-7

How Do I Complete the Application for IRS Individual Taxpayer Identification Number (Form W-7)?

We strongly recommend working with a professional because if your Form W-7 has any mistakes, your ITIN Application will be rejected by the IRS.

However, if you would like to see what the application looks like and see the instructions to fill out the form on your own:

📌 Follow instructions from the IRS to download Form W-7, or

📌 You can download a copy of Form W-7.

How Do I Submit My Application to the IRS?

Per the Instructions for Form W-7 (please see the link for the most updated version, the details below are directly added from the Instructions):

✔️ By mail:

Mail Form W-7, your tax return (if applicable) or other documents required by an exception, and the documentation described under Supporting Documentation Requirements earlier, to:

Internal Revenue Service ITIN Operation P.O. Box 149342Austin, TX 78714-9342

If you mail your application, don’t use the mailing address in the instructions for your tax return.

✔️ By private delivery services:

If you use a private delivery service, submit your Form W-7, your tax return (if applicable) or other documents required by an exception, and the documentation described under Supporting Documentation Requirements, earlier, to:

Internal Revenue Service ITIN Operation Mail Stop 6090-AUSC3651 S. Interregional, Hwy 35Austin, TX 78741-0000

The private delivery service can tell you how to get written proof of the mailing date.

✔️ In person:

You can apply for ITIN by visiting designated IRS Taxpayer Assistance Centers (TACs).

They can verify original documentation and certified copies of the documentation from the issuing agency for primary and secondary applicants and their dependents.

For dependents, TACs can verify passports, national identification cards, and birth certificates. These documents will be returned to you immediately. Service at TACs is by appointment only.

Schedule your appointments by calling 844-545-5640.

See IRS.gov/W7DocumentVerification for a list of designated TACs that offer ITIN document authentication service.

TACs that don’t offer ITIN document authentication service will mail the original documents, Form W-7, and the tax return to the IRS Austin Service Center for processing.

✔️ Through an acceptance agent:

You can also apply through one of the two types of acceptance agents authorized by the IRS.

📌 Acceptance Agent (AA)

An Acceptance Agent (AA) can help you complete and file Form W-7. To get a list of agents, visit IRS.gov and enter “acceptance agent program” in the search box.

Your AA will need to submit original documentation or certified copies of the documentation from the issuing agency to the IRS for all applicants.

📌 Certifying Acceptance Agent (CAA)

A Certifying Acceptance Agent (CAA) can verify original documentation and certified copies of the documentation from the issuing agency for primary and secondary applicants and their dependents, except for foreign military identification cards.

For dependents, CAAs can only verify passports and birth certificates. The CAA will return the documentation immediately after reviewing its authenticity.

Taxpayers residing outside of the United States can apply for ITIN through a CAA.

Learn everything about State-Specific ITIN Requirements before you apply for one.

Is There an Exception for Getting an ITIN for LLC Owners?

Yes — there is a limited exception.

Normally, an ITIN application must be submitted along with a U.S. federal tax return. However, under Exception 1(a) listed in Form W-7 instructions, certain LLC owners and partners may apply without attaching a tax return.

📌 Who Qualifies Under Exception 1(a)?

Individuals who are:

• Partners of a U.S. or foreign partnership (including certain LLCs treated as partnerships),
• That invests in the United States, and
• Owns income-generating assets subject to IRS information reporting and federal tax withholding.

This exception is particularly relevant for international founders and foreign LLC members who need an ITIN for withholding and reporting purposes before filing their first tax return.

📌 Required Documentation for Exception 1(a)

If claiming Exception 1(a), you must submit:

• A copy of the relevant portion of the partnership or LLC agreement
• The partnership’s Employer Identification Number (EIN)
  
• Proof that you are a partner/member
• Documentation showing the entity conducts business in the U.S. and generates reportable income

The EIN is issued by the Internal Revenue Service.

 

 

How Do I Complete Form W-7?

Form W-7 is the official Application for IRS Individual Taxpayer Identification Number.

While you can complete it yourself, even small errors often result in rejection. The IRS is strict about:

• Matching name formats
• Properly selecting the reason code
• Submitting certified identification documents
• Attaching required exception documentation (if applicable)

If you prefer to review the form yourself, you can download Form W-7 and follow the official IRS instructions.

How Do I Submit My ITIN Application?

According to the most recent IRS instructions, you can apply in four ways:

✔️ 1. By Mail

Mail your completed Form W-7, tax return (if required), and supporting documentation to:

Internal Revenue Service
ITIN Operation
P.O. Box 149342
Austin, TX 78714-9342

Do not use the regular tax return mailing address.

✔️ 2. By Private Delivery Service

Send documents to:

Internal Revenue Service
ITIN Operation
Mail Stop 6090-AUSC
3651 S. Interregional Hwy 35
Austin, TX 78741-0000

Your delivery provider can provide proof of mailing.

✔️ 3. In Person (IRS Taxpayer Assistance Center – TAC)

You can apply in person at designated IRS Taxpayer Assistance Centers (TACs).

TACs can:

• Verify original identification documents
• Authenticate certified copies
• Return documents immediately

Appointments are required and can be scheduled by calling 844-545-5640.

Note: Not all TACs provide ITIN document authentication services.

✔️ 4. Through an Acceptance Agent

The IRS authorizes two types of agents:

📌 Acceptance Agent (AA)

• Helps prepare and submit Form W-7
• Must send original or certified documents to the IRS

📌 Certifying Acceptance Agent (CAA)

• Can verify identity documents themselves
• Returns documentation immediately
• Ideal for applicants outside the U.S.

Taxpayers residing outside the United States can apply through a CAA without mailing original passports to the IRS.

Key Takeaways for International Founders (2026)

• Most applicants must attach a tax return.
• Exception 1(a) may allow LLC partners to apply without one.
• Passport is the easiest document for identity + foreign status.
• Errors in Form W-7 frequently lead to delays of 8–12 weeks or more.
• Applying through a CAA is often the safest and fastest route for founders outside the U.S.

Disclaimer: The content on this website is for informational purposes only and does not constitute legal, financial, or professional advice. Please consult qualified experts before acting on any information. K M GATECHA & CO LLP accepts no liability for errors, omissions, or outcomes from the use of this content. This site is not an advertisement or solicitation.