How to Apply for an ITIN as a Non-Resident: A Complete Step-by-Step Guide

US Non-Resident ITIN Application Procedures

If you're a non-resident foreign national earning income from U.S. sources, it's essential to understand the process of obtaining an ITIN (Individual Taxpayer Identification Number). This unique number is issued by the IRS (Internal Revenue Service) for individuals who are not eligible to obtain a Social Security Number (SSN) but are required to report and pay U.S. taxes.

From real estate investments to royalties, dividends, or even business ownership, there are many scenarios where non-residents need to file U.S. taxes. However, applying for an ITIN can seem complicated, especially with all the paperwork, identification requirements, and IRS procedures involved. Making a mistake or submitting incomplete forms can lead to rejection and delay, which is why it's critical to get every step right the first time.

In this guide, you'll find everything you need to know about applying for an ITIN as a non-resident, including eligibility, required documents, how to complete Form W-7, common errors to avoid, and answers to frequently asked questions. Whether you're investing in U.S. property, receiving passive income, or running a U.S. business as a foreigner, this article will help ensure you go through the ITIN application process smoothly and effectively.

Let’s dive into the full process of how to apply for an ITIN from start to finish, even if you're applying from outside the United States.

What Is an ITIN?

The Individual Taxpayer Identification Number (ITIN) is a tax processing number issued by the IRS for people who need to file or report taxes in the U.S. but are not eligible for a Social Security Number (SSN). It’s a 9-digit number starting with “9” and is used only for federal tax reporting.

ITINs are used by:

Foreign investors in U.S. real estate or stocks
Non-resident spouses or dependents of U.S. citizens/residents
International students, scholars, or researchers receiving U.S.-based income
Foreign business owners or partners in U.S. LLCs or corporations

Importantly, an ITIN does not authorize work in the U.S. or offer immigration benefits. It solely allows individuals to comply with U.S. tax laws.

Who Needs an ITIN?

You need an ITIN if:

You are a non-resident foreign national with U.S.-source income
You’re a spouse or dependent of a U.S. citizen/resident filing jointly or being claimed
You're a foreign partner in a U.S. business or own real estate in the U.S.
You receive income like rental earnings, royalties, or dividends from the U.S.
You're filing a U.S. tax return but are not eligible for an SSN

For example, many South Korean investors in U.S. real estate or the stock market are required to get an ITIN to pay taxes or claim treaty benefits.

Required Documents for ITIN Application

To apply for an ITIN, you must prepare:

Form W-7 (Application for IRS Individual Taxpayer Identification Number)
Federal income tax return (Form 1040-NR) – usually submitted with the application
Passport (original or certified copy) – this is the only document that can stand alone for both identity and foreign status
Supporting documentation explaining the reason you need an ITIN (such as rental agreements, dividend statements, or U.S. business income proof)

How to Fill Out Form W-7

Here’s how to complete Form W-7 step by step:

Line 1a & 1b: Full name as shown on your passport and birth name if different
Line 2: Foreign mailing address
Line 3: U.S. address (can be your tax preparer’s address)
Line 4: Date of birth and place of birth
Line 6a–6g: Citizenship, passport number, issuing country, and date of entry into the U.S. (if applicable)
Signature: The applicant or their authorized representative must sign

Make sure all information exactly matches your passport. Any mismatch can lead to rejection.

How to Submit Passport Copy Correctly

To avoid mailing your original passport (which is not recommended), you can do one of the following:

Use a Certified Acceptance Agent (CAA) – an IRS-authorized agent who verifies your identity and sends your W-7 directly to the IRS
Obtain a certified copy from the issuing agency (for example, the Korean government office)
Get your passport certified at a U.S. Embassy or Consulate

This step is crucial—improper ID submission is one of the top reasons ITIN applications are rejected.

How Non-Residents Can Apply for an ITIN from Abroad

If you're outside the U.S., you can submit your ITIN application by:

Mailing the application to the IRS (Austin, TX address). However, this requires sending original identification documents or certified copies
Working with a Certified Acceptance Agent (CAA) who can verify your passport and submit everything for you
Visiting a U.S. Embassy/Consulate to certify your passport and submit via mail

Using a CAA is the safest and fastest method, especially for international applicants.

When and How Long It Takes to Get an ITIN

You can apply for an ITIN any time of the year, though it's commonly done between January and April during tax season. After submitting, it usually takes 7–11 weeks to receive your ITIN. This timeline can vary depending on IRS workload and how complete your application is.

You’ll receive a letter from the IRS (Notice CP565) with your ITIN once approved.

How Long Is an ITIN Valid?

ITINs expire if not used on a tax return at least once in three consecutive years. Expired ITINs must be renewed before filing a new tax return.

To renew an expired ITIN, file Form W-7 again with updated documents and indicate your prior ITIN number.

Why ITIN Applications Are Rejected

Common reasons for ITIN rejection:

Missing or uncertified passport copy
Incorrect or incomplete Form W-7
Missing U.S. tax return (Form 1040-NR)
No clear explanation of ITIN need
Inconsistent data (names, addresses, birthdates)

Double-check everything and consider using a tax professional or Certified Acceptance Agent to avoid these issues.

What Is a Certified Acceptance Agent (CAA)?

A CAA is authorized by the IRS to verify original documents and assist with ITIN applications. Using a CAA means:

You don’t need to mail original documents
Your application is reviewed for errors before submission
The process is faster and safer for international applicants

You can find a list of CAAs on the official IRS website.

What You Can Do with an ITIN

Once you have an ITIN, you can:

File U.S. tax returns
Receive tax refunds
Report income from U.S. sources
Comply with U.S. tax laws as a real estate investor or business owner
Claim benefits from tax treaties (like Korea–U.S. tax treaty)
Sometimes open a U.S. bank account

Note: ITIN does not authorize you to work in the U.S. or act as proof of immigration status.

How to Check the Status of Your ITIN Application

If you haven’t received your ITIN after 11 weeks, you can:

Call the IRS International Taxpayer number: +1-267-941-1000
Use a tax professional or CAA to check your application status

You’ll need to provide your full name, mailing address, and other application details.

What to Do If You Lose Your ITIN

If you lose your ITIN:

Check your past tax returns – it may be listed there
Call the IRS and verify your identity to recover the number
File Form W-7 again and mark it as a renewal or “ITIN lost”

Don’t apply for a new ITIN if you already had one—this can cause IRS confusion.

Tips for Korean Applicants

Write all documents in English and match names to your passport
Use your Korean address in English on Form W-7
Use a U.S. mailing address if available (e.g., your CPA or tax agent)
Consider working with a U.S.-based tax preparer or CAA
Prepare U.S. income documents like real estate rental agreements or dividend statements

ITIN and U.S. Tax Filing

Having an ITIN doesn’t exempt you from tax filing obligations. In fact, you must:

File a U.S. tax return annually (Form 1040-NR for most non-residents)
Report all U.S.-source income, including rent, dividends, and royalties
Consider applying U.S.–Korea tax treaty benefits where available

Failing to file taxes can result in penalties, back taxes, or disqualification from future benefits.

Frequently Asked Questions (FAQ)

How long does it take to get an ITIN?
Typically 7 to 11 weeks, depending on IRS processing times.

Can I apply without sending my original passport?
Yes. Use a CAA or get a certified copy from your government or embassy.

Is the ITIN valid forever?
No. It expires after 3 years of inactivity and must be renewed.

Can I apply for an ITIN without filing a tax return?
Only in limited exceptions. Most applicants must file a tax return with Form W-7.

Can I open a bank account with an ITIN?
Some banks accept ITINs, but it varies by institution.

Do I need an ITIN as a real estate investor?
Yes, to report income, claim deductions, and file taxes.

How do I renew my ITIN?
Resubmit Form W-7 with updated documents and indicate it’s a renewal.

Can Koreans apply for an ITIN from Korea?
Yes. Use a CAA or mail your application to the IRS.

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