Free Guide to ITIN Numbers and Requirements

What an ITIN Number Is and Why People Need One

An Individual Taxpayer Identification Number, or ITIN, is a nine-digit tax number issued by the Internal Revenue Service (IRS). The number follows the same format as a Social Security Number (SSN)—formatted as XXX-XX-XXXX—but it serves a different purpose. While a Social Security Number is linked to employment and benefits, an ITIN is specifically designed to help people file taxes and report income to the federal government.

The IRS created the ITIN program in 1996 to allow people without Social Security Numbers to meet their tax obligations. This includes people who are not authorized to work in the United States, people on certain visa types, foreign nationals with U.S. income, and dependents or spouses who don't have SSNs. According to IRS data, the agency issues roughly 1.4 million ITINs each year, and there are over 16 million valid ITINs currently in use.

Having an ITIN allows a person to file federal income tax returns, which is important for several reasons. First, if taxes were withheld from paychecks during the year, filing a return may result in a refund. Second, filing establishes a tax record with the government. Third, for people hoping to eventually gain lawful permanent resident status or citizenship, demonstrating a history of tax compliance can be relevant to immigration matters.

An ITIN is not the same as a work authorization document. Someone with an ITIN cannot use it to legally work in the United States. The ITIN only relates to tax reporting and filing. However, in practice, many people with ITINs do work and pay taxes, and the ITIN helps them report that income correctly.

Practical Takeaway: An ITIN is a nine-digit number that allows people without Social Security Numbers to file federal taxes and report income to the IRS. It's focused on tax compliance, not work authorization.

Who Needs an ITIN and Common Situations

Several categories of people may need or benefit from having an ITIN. Understanding which situations call for an ITIN helps determine whether pursuing one makes sense for a particular person's circumstances.

Non-residents and foreign nationals with U.S. income represent one major group. If someone lives outside the United States but earned income from U.S. sources—such as rental income from property, investment income, or self-employment income—they typically need an ITIN to file a U.S. tax return and report that income. A foreign national working temporarily in the United States on a visa type that doesn't provide a Social Security Number may also need an ITIN to file taxes on their U.S. wages.

Spouses and dependents who are not U.S. citizens or permanent residents sometimes need ITINs. If a U.S. citizen files taxes as married filing jointly, but their spouse doesn't have a Social Security Number, the spouse may obtain an ITIN to be included on the joint return. Similarly, a dependent child or family member living in the household who doesn't have an SSN can be issued an ITIN to be claimed as a dependent on a tax return, which can increase deductions or credits for the household.

Self-employed individuals without SSNs need ITINs to report business income and file Schedule C forms. Freelancers, contractors, or small business owners fall into this category. Additionally, anyone receiving certain types of income—including investment income, interest, or income from rental property—typically must have a tax identification number to report it.

Students and exchange visitors on F-1, J-1, or M-1 visa status who work on or off campus may need ITINs if they don't have SSNs. International students who earn income during their time in the United States are required to report that income to the IRS.

Practical Takeaway: Common situations requiring an ITIN include: foreign nationals with U.S. income, spouses or dependents without SSNs, self-employed people without SSNs, and students on certain visa types with earned income.

How the ITIN Application Process Works

The process of obtaining an ITIN involves submitting Form W-7 (Application for IRS Individual Taxpayer Identification Number) directly to the IRS. Unlike many government processes, there is no online application for an ITIN—the application must be submitted by mail or in person at an IRS office. The form itself is straightforward and requests basic personal information including name, date of birth, country of citizenship, and mailing address.

The completed Form W-7 must be accompanied by original documents or certified copies that establish identity and foreign status. Acceptable identity documents vary based on the applicant's country of citizenship and may include a foreign passport, national identification card, visa, driver's license, or birth certificate. The specific documents required depend on the country of origin, and the IRS provides a detailed list showing which documents are acceptable for each country.

Additionally, the application requires documents showing the reason for the ITIN request. If the person is filing a tax return, a copy of the return (such as Form 1040) should be included. If someone is claiming a dependent, a birth certificate or other proof of relationship may be needed. If the person received income from self-employment or investments, documents showing that income—such as 1099 forms, rental agreements, or business records—help establish the need for an ITIN.

The IRS processes ITIN applications by mail, and the process typically takes 4 to 6 weeks during normal periods, though processing times can be longer during tax season (January through April). Some IRS offices offer in-person ITIN services at Taxpayer Assistance Centers, which may process applications more quickly. The IRS does not charge a fee for issuing an ITIN.

Once the ITIN is issued, the applicant receives a notice by mail. The ITIN is permanent and does not expire, though the IRS has implemented rules that may affect ITINs that are not used to file a tax return for three consecutive years. If an ITIN is not used during a three-year period, it may become inactivated, and the person would need to reactivate it or obtain a new one.

Practical Takeaway: To obtain an ITIN, submit Form W-7 by mail to the IRS with original or certified identity documents and documents proving the reason for the ITIN request. Processing typically takes 4 to 6 weeks.

Required Documents and Identity Verification

Submitting the correct documents is critical to an ITIN application's success. The IRS requires original documents or certified copies—photocopies alone are not acceptable. Understanding which documents meet IRS standards helps prevent delays or rejection of the application.

For identity documentation, a foreign passport is the most widely accepted document and is considered primary evidence of identity and foreign status for nearly all countries. A national identification card issued by the applicant's home country—if it contains a photograph, date of birth, and signature—is also generally acceptable. A visa stamped in a passport, a travel document, a driver's license (if issued by a foreign country), or a birth certificate (if issued by a civil authority) may also satisfy identity requirements, though the IRS may have different rules depending on the person's country of citizenship.

The IRS publishes a comprehensive country-by-country list showing which documents are acceptable identity evidence for applicants from each nation. This list is updated periodically and is available on the IRS website. Before submitting an application, reviewing this list ensures the documents being submitted will be accepted.

In addition to identity documents, the applicant must provide documentation showing the reason for requesting an ITIN. For someone filing a tax return, a copy of the completed Form 1040 (U.S. Individual Income Tax Return) or other relevant tax form must be included. For people claiming dependents, a birth certificate and proof of relationship—such as a marriage certificate or adoption papers—should be provided. For self-employed individuals, business records, invoices, or 1099 forms from clients or customers demonstrate income.

Certified copies are acceptable if original documents cannot be provided, but these must be certified by the issuing authority or a notary public in the applicant's country or in the United States. Regular photocopies or scans are not sufficient. When documents are in a language other than English, the applicant should include a certified English translation prepared by