What is itin?

Question

ITINMay 24, 2026

What is itin?

An ITIN is a tax processing number issued by the IRS to individuals who need a U.S. taxpayer identification number but do not have and are not eligible to obtain a Social Security number.

— Anonymous

1 Answer

Gokce Tandogdu ITIN Specialist, itin.net May 24, 2026 · Accepted Answer · 2026-05-24

An Individual Taxpayer Identification Number (ITIN) is a tax processing number issued by the U.S. Internal Revenue Service (IRS). It is for certain resident and nonresident aliens, their spouses, and dependents who cannot get a Social Security number (SSN). The ITIN is used for U.S. federal tax purposes only. The IRS issues ITINs to identify taxpayers who are not eligible for an SSN. The structure of an ITIN is nine digits, and like an SSN, it is formatted as XXX-XX-XXXX. The IRS assigns ITINs regardless of immigration status. The number is always a nine-digit number, beginning with the number 9. It is formatted as a Social Security number, with the fourth and fifth digits ranging from 50 to 65, 70 to 88, and 90 to 99. The IRS issues ITINs to individuals who are required to have a U.S. taxpayer identification number for tax purposes but do not have, and are not eligible to obtain, an SSN. Answering the question of "what is itin" leads to understanding its role in the U.S. tax system for non-U.S. persons.

Who Needs an ITIN?

You need an ITIN if you are a foreign national or non-resident alien and are required to file a U.S. tax return or are claimed as a dependent on a U.S. tax return, but you are not eligible for an SSN. This includes a variety of situations:

Non-resident aliens filing a U.S. tax return: If you have U.S. source income that is subject to U.S. tax withholding, and you are not eligible for an SSN, you will need an ITIN to file your tax return (such as Form 1040-NR, U.S. Nonresident Alien Income Tax Return) to report the income and claim any applicable deductions or credits. This is common for individuals receiving income from U.S. investments, royalties, or certain services performed in the U.S.
Resident aliens filing a U.S. tax return: Certain resident aliens who are not eligible for an SSN must also obtain an ITIN to file their federal tax returns. This can include individuals who have obtained a green card but have not yet received an SSN, or individuals who have met the substantial presence test but are not eligible for an SSN.
Dependents claimed on a U.S. tax return: If a dependent is listed on a U.S. tax return and that dependent is a foreign national not eligible for an SSN, an ITIN is required for that dependent.
Spouses claimed on a U.S. tax return: Similar to dependents, if a spouse is claimed on a U.S. tax return and is not eligible for an SSN, an ITIN is required for the spouse.
Individuals claiming tax treaty benefits: Even if you are not otherwise required to file a U.S. tax return, you may need an ITIN to claim benefits under a U.S. tax treaty. For example, if you are receiving certain types of income from U.S. sources that are subject to reduced withholding rates under a tax treaty, you may need an ITIN to claim those benefits.
Individuals filing Form 5472: Non-resident aliens who own a U.S. business, such as a U.S. disregarded entity owned by a foreign person, are required to file Form 5472, Information Return of a 25% Foreign-Owned U.S. Corporation or a Foreign Corporation Engaged in a U.S. Trade or Business, and Form 1120 (if applicable). To file these forms, an ITIN is generally required for the individual owner if they do not have an SSN. This is a critical filing for foreign individuals operating U.S. businesses. You can learn more about U.S. LLC formation and its tax implications.

It is important to note that an ITIN does not provide eligibility for employment in the United States, nor does it authorize an individual to work in the U.S. It also does not provide eligibility for Social Security benefits. The primary purpose of the ITIN is strictly for U.S. tax reporting.

How to Apply for an ITIN

The application process for an ITIN involves completing and submitting Form W-7, Application for IRS Individual Taxpayer Identification Number. This form requires you to provide your legal name, address, and foreign tax identification number (if applicable). You must also provide documentation to verify your identity and foreign status. The IRS has established specific procedures and acceptance agents to assist with this application. You can apply for an ITIN in one of several ways:

Mail: You can mail your completed Form W-7, along with original or certified copies of your identification documents, and your U.S. federal income tax return (if required) to the IRS address listed in the Form W-7 instructions. The IRS will review your application and supporting documents and will mail your ITIN back to you. This method can involve significant processing times, and the IRS will keep your original identification documents until the process is complete.
IRS Taxpayer Assistance Centers (TACs): Certain IRS TACs offer in-person ITIN application services. You can make an appointment at an IRS TAC and bring your completed Form W-7, identification documents, and tax return. The IRS employee will review your documents and forward your application to the ITIN processing center. This can be a faster way to apply, as you get your original documents back the same day.
Certified Acceptance Agents (CAAs): This is often the most convenient method for applicants outside the U.S. CAAs are individuals or entities (like itin.net) authorized by the IRS to help taxpayers apply for ITINs. A CAA can review your application and verify your original identification documents, sending certified copies to the IRS. This means you do not have to mail your original documents, reducing the risk of loss. The CAA submits the application on your behalf. This process is designed to be efficient and secure.

When applying, you generally need to submit your U.S. federal income tax return for which the ITIN is needed, unless you meet an exception. Exceptions include applying for an ITIN for a dependent, spouse, or to claim tax treaty benefits, where the tax return may not be required at the time of application. Always consult the latest instructions for Form W-7 for specific requirements and exceptions.

Required Documentation for ITIN Application

To successfully apply for an ITIN, you must provide documentation that proves both your identity and your foreign status. The IRS requires original documents or certified copies from the issuing agency. Accepted documents typically include:

Passport: This is the preferred document as it verifies both identity and foreign status. If your passport is expired, you can use it if it was valid when issued for the intended period of admission to the U.S. or if it has a valid entry visa.
National Identity Card: This must show your name, photograph, address, date of birth, and expiration date.
U.S. Driver's License: Must contain all the above information.
Civil Birth Certificate: This is acceptable for dependents under 18 years of age.
Foreign Driver's License: Must contain all the above information.
Foreign Military Identification Card: Must contain all the above information.
National Health Insurance Card: Must contain all the above information.
Voter's Identity Card: Must contain all the above information.
Visa: If you are not a U.S. citizen, you can present a visa along with your passport.

If you cannot provide a passport, you can submit a combination of other documents to prove both identity and foreign status. For example, a birth certificate (for identity) combined with a driver's license (for identity and foreign status, if applicable). The IRS provides a detailed list of acceptable documents and combinations in the Form W-7 instructions. When using a CAA, they will help you ensure your documentation meets IRS requirements. itin.net is a CAA that assists individuals in gathering and submitting the necessary documentation.

Processing Times for ITIN Applications

The IRS processing times for ITIN applications can vary significantly. Historically, processing could take anywhere from 4 to 11 weeks, especially during peak tax seasons. However, the IRS has faced backlogs, and processing times can extend beyond these estimates. If you mail your application, you will receive a letter from the IRS with your ITIN, typically designated as Letter CP565, once it has been assigned. It is advisable to apply well in advance of any tax filing deadlines to avoid delays. If you are applying through an IRS Taxpayer Assistance Center or a Certified Acceptance Agent, the initial review may be quicker, but the ultimate assignment of the ITIN is still done by the IRS ITIN Operation. The IRS does not charge a fee to apply for an ITIN. You should be wary of any service that charges a fee for the ITIN application itself, though CAAs may charge service fees for their assistance.

ITIN Renewal and Updates

ITINs do not expire automatically, but the IRS has implemented a renewal program for ITINs that have not been used on a federal tax return for three consecutive tax years. Additionally, certain ITINs with specific middle digits were subject to expiration and required renewal. The IRS began a phased renewal process starting in 2019. If your ITIN has expired and you need to file a tax return, you must renew it. You can renew your ITIN by submitting a Form W-7 along with a valid U.S. federal income tax return and required identification documents. The IRS will issue a notice, such as Letter CP48, if your ITIN needs renewal and you have not used it. It's crucial to keep your ITIN on record and understand its status, especially if you anticipate needing it for future tax filings or other financial transactions in the U.S., such as opening a U.S. bank account.

Common Mistakes When Applying for an ITIN

Several common mistakes can lead to delays or rejections of ITIN applications. Understanding these pitfalls can help ensure a smoother process:

Incomplete Form W-7: Missing information, such as a required signature or incorrect personal details, will cause delays. Ensure all fields are accurately completed.
Lack of or Incorrect Identification Documents: Not providing the required identification documents, or submitting documents that do not meet IRS specifications (e.g., not original or certified copies, or missing required information on the document), is a frequent issue. Ensure your documents are valid and meet the criteria outlined in the Form W-7 instructions.
Missing Tax Return: For most applicants, Form W-7 must be submitted with a valid U.S. federal income tax return. Failure to include this, unless an exception applies, will result in rejection.
Incorrectly Certified Documents: If you are not using a CAA, and are mailing certified copies, ensure they are certified by the issuing agency (e.g., the embassy or consulate of the country that issued your passport) or by the IRS directly. CAAs are authorized to certify documents, which simplifies this step.
Not Understanding Exceptions: Not being aware of the specific exceptions to the tax return filing requirement can lead to unnecessary delays. For instance, if you are applying solely to claim tax treaty benefits, you might not need to file a return simultaneously.
Using Expired ITIN: If your ITIN has expired due to non-use and you need to file a tax return, you must go through the renewal process. Trying to use an expired ITIN can lead to issues with your tax filing.

ITIN vs. SSN

It is vital to distinguish between an ITIN and a Social Security number (SSN). An SSN is issued by the Social Security Administration (SSA) and is primarily used for tracking earnings for Social Security benefits and for employment purposes. Most U.S. citizens, permanent residents, and certain temporary workers are eligible for an SSN. An ITIN, on the other hand, is issued by the IRS exclusively for tax purposes. It does not grant any work authorization or immigration benefits. If you become eligible for an SSN, you must obtain one and stop using your ITIN. Your SSN will then be used for all tax filing purposes. The IRS will automatically convert your ITIN to an SSN once they are notified by the SSA that you have been issued an SSN. You do not need to apply for an ITIN if you have an SSN or are eligible to get one.

When to Seek Professional Help

While the ITIN application process is designed to be accessible, complex situations may warrant professional assistance. If you are unsure about your tax filing obligations, the documentation required, or if you have a complicated tax situation involving foreign income, U.S. business ownership, or tax treaty benefits, consulting with a qualified tax professional or an Acceptance Agent is highly recommended. Professionals can help ensure your application is accurate and complete, increasing the likelihood of timely approval. For assistance with ITIN applications, consider the services offered by itin.net, a Certified Acceptance Agent. For broader tax advice related to your specific circumstances, seeking guidance from a tax attorney or Enrolled Agent is advisable. You can also find more information on tax-related topics on the itin.net blog or our Q&A index.