ITIN vs Social Security Number for Non-U.S. Residents

An Individual Taxpayer Identification Number (ITIN) and a Social Security Number (SSN) are both nine-digit U.S. tax identification numbers — but different agencies issue them, serve different purposes, and apply to entirely different groups of people. For non-U.S. residents with U.S. tax obligations, understanding which number applies to your situation is essential before you file a tax return, claim a refund, or report U.S. income.

If you are a non-U.S. resident who earns U.S. income, owns U.S. property, or has any U.S. tax filing obligation but cannot obtain a Social Security Number, you almost certainly need an ITIN. Filing with the wrong number — or no number at all — leads to rejected returns, lost refunds, and IRS correspondence that can take months to resolve.

What Is a Social Security Number (SSN)?

A Social Security Number is a nine-digit identifier (format: XXX-XX-XXXX) issued by the U.S. Social Security Administration (SSA) — not the IRS. It was created to track workers’ earnings over their lifetime and determine entitlement to Social Security retirement and disability benefits. Over time, the SSN has become the primary identification number used across the U.S. financial and government systems.

Who qualifies for an SSN:

• U.S. citizens (SSNs are typically assigned at birth)
• Lawful permanent residents (green card holders)
• Non-citizens authorized to work in the United States — including certain visa holders such as H-1B, L-1, F-1 students with work authorization, and J-1 exchange visitors with work authorization

What an SSN is used for:

• Filing U.S. federal and state income tax returns
• Employment — employers use it to report wages to the IRS via Form W-2
• Applying for Social Security retirement and disability benefits
• Opening bank accounts, applying for credit cards, and using most financial services
• Driver’s licenses, professional licenses, and government benefits
• Background checks and identity verification across most sectors

Important: If you are eligible for an SSN, you must apply for one — you cannot request an ITIN instead. The IRS will reject an ITIN application if the applicant qualifies for an SSN.

What Is an ITIN?

An Individual Taxpayer Identification Number (ITIN) is a nine-digit tax processing number issued by the Internal Revenue Service (IRS) — not the SSA — to individuals who have a U.S. federal tax filing or reporting obligation but are not eligible for a Social Security Number. ITINs always begin with the number 9 and follow the same format as an SSN: 9XX-XX-XXXX.

The IRS created the ITIN program so that non-U.S. residents and others without SSNs can comply with U.S. tax law — paying taxes owed, filing returns, and claiming refunds — without needing work authorization or legal residency status. As of October 2025, the IRS had issued approximately 31 million ITINs since the program began, with around 5 million currently active.

Who qualifies for an ITIN:

• Nonresident aliens required to file a U.S. tax return
• Non-U.S. residents with U.S. rental income, investment income, or business income
• Foreign sellers of U.S. real property subject to FIRPTA withholding
• Spouses or dependents of U.S. citizens or residents who are listed on a U.S. tax return
• Spouses or dependents of nonresident aliens holding U.S. visas
• Non-U.S. residents claiming benefits under a U.S. income tax treaty

What an ITIN is used for:

• Filing Form 1040-NR (U.S. Nonresident Alien Income Tax Return)
• Claiming tax refunds from U.S. withholding
• Reporting U.S. rental, investment, or business income to the IRS
• Applying for FIRPTA withholding certificates (Form 8288-B) when selling U.S. property
• Claiming treaty-reduced withholding rates on U.S.-source income
• Opening certain bank accounts at institutions that accept ITINs in place of an SSN

What an ITIN cannot do:

• Authorize you to work in the United States
• Provide access to Social Security retirement or disability benefits
• Serve as a government-issued ID outside of the tax system
• Establish immigration status or legal residency

ITIN vs SSN: Side-by-Side Comparison

Can You Have Both an ITIN and an SSN?

No. You cannot hold an ITIN and a Social Security Number at the same time. The IRS requires that if you become eligible for an SSN — for example, because you receive work authorization or permanent residency — you must notify the IRS and stop using your ITIN. The IRS will then deactivate the ITIN and associate your prior tax filings with your new SSN.

If your immigration or work status changes and you receive an SSN after previously holding an ITIN, contact the IRS to have your records merged. Continuing to file with an ITIN after obtaining an SSN is an error that can complicate your tax history.

Does an ITIN Expire?

Yes. Unlike a Social Security Number, an ITIN expires if it is not used on a U.S. federal tax return for three consecutive calendar years. ITINs with certain middle digit combinations issued before 2013 have also been deactivated by the IRS under a phased expiration schedule.

If your ITIN expires before you file a return, you must renew it by submitting a new Form with your return, rather than filing it separately. Attempting to file with an expired ITIN results in processing delays and may cause you to lose access to certain tax credits for that year.

How long it takes to get or renew an ITIN depends on the time of year and your submission method — the IRS recommends applying well before your filing deadline.

Who Specifically Needs an ITIN?

The question non-U.S. residents most commonly ask is whether their specific situation requires an ITIN. Determining your U.S. residency status for tax purposes is the starting point — the IRS applies the substantial presence test and the green card test to decide whether you are treated as a U.S. resident or nonresident for tax purposes.

Once residency status is confirmed, an ITIN is required in the following situations:

Rental income from U.S. property

Non-U.S. residents who own U.S. rental property must report that income to the IRS and file Form 1040-NR. An ITIN is required to do so. Owners who want to deduct expenses — mortgage interest, repairs, depreciation — also need an ITIN, since those deductions require a properly filed tax return. Without an ITIN, the IRS applies a flat 30% withholding rate on gross rental income with no deductions allowed.

Investment income — stocks, dividends, and interest

Non-U.S. residents who receive U.S. dividends, interest, or other investment income may be subject to U.S. withholding tax. An ITIN is required to claim a reduced withholding rate under a tax treaty or to file a return and recover excess withholding. The ITIN requirements for non-residents with U.S. investment income cover this in detail.

Sale of U.S. real property

When a foreign person sells U.S. real estate, FIRPTA requires the buyer to withhold 15% of the gross sale price. Both the seller’s and buyer’s tax ID numbers must appear on the required IRS forms. Getting an ITIN before or at the time of a property sale is essential — without one, the withholding process stalls and refunds are delayed.

Freelance and self-employment income from U.S. clients

Non-U.S. residents who earn income from U.S. companies or clients — whether through platforms like Upwork, direct contracts, or consulting arrangements — typically have a U.S. tax filing obligation. The ITIN application process for freelancers earning U.S. income explains when an ITIN is required versus when a Form W-8BEN is sufficient.

YouTube, content creation, and digital platform income

Non-U.S. content creators receiving payments from YouTube AdSense, Patreon, or other U.S.-based platforms are subject to U.S. withholding — typically 24% without a valid tax ID. YouTubers and content creators earning U.S. income need an ITIN to claim treaty-reduced withholding rates or to file a return and recover excess amounts.

Canadian residents with U.S. property or income

Canadians are among the most common ITIN applicants. Whether buying or selling U.S. real estate, earning rental income, or receiving U.S. dividends, Canadian residents are subject to U.S. tax rules and require an ITIN. The complete guide for Canadian real estate investors covers ITIN and FIRPTA requirements specific to Canadian residents.

What Happens If You Don’t Get an ITIN When You Need One?

Failing to obtain an ITIN when required is not a minor oversight — the consequences are concrete and directly affect your money. Not applying for an ITIN when you need one can result in:

• Rejected tax returns — the IRS requires an ITIN on every return; without one, the return cannot be processed
• Lost refunds — withheld amounts remain with the IRS if no return is filed to claim them back
• Flat 30% withholding on U.S.-source income with no ability to claim treaty rates or deductions
• Delayed real estate transactions — FIRPTA withholding certificates and refunds require a valid ITIN
• IRS penalties — for failure to file or failure to pay taxes owed

How to Apply for an ITIN

Applying for an ITIN requires completing IRS Form W-7 and submitting it with proof of identity, proof of foreign status, and, in most cases, a completed U.S. federal tax return. The IRS accepts 13 types of documents; a valid passport is the only one that satisfies both the identity and foreign-status requirements on its own.

There are three ways to submit your ITIN application:

1. Mail directly to the IRS — original documents or certified copies sent to IRS ITIN Operations, P.O. Box 149342, Austin, TX 78714-9342. Original documents are returned within 60 days.
2. In person at an IRS Taxpayer Assistance Center (TAC) — staff authenticate your documents on the spot. By appointment only.
3. Through an IRS-authorized Certifying Acceptance Agent (CAA) — the CAA verifies and certifies your documents, so you do not need to mail your original passport. Nolly.com is an IRS-authorized CAA.

What documents you need for an ITIN application — and why each one matters — walks through the full list with country-specific guidance. For applicants who prefer not to send their passport internationally, it is possible to apply without mailing your passport through a CAA like Nolly.com.

The standard ITIN processing time is 7 weeks outside of tax season, and 9–11 weeks during the peak filing period (January 15 to April 30) or for applications submitted from overseas. Common reasons ITIN applications are rejected — and how to avoid them — are worth reviewing before you submit.

ITIN vs SSN: Which One Do You Need?

Apply for Your ITIN Through Nolly.com

Nolly Services Inc (Nolly.com) is an IRS-authorized Certifying Acceptance Agent based in Toronto, Canada. As a CAA, Nolly.com certifies your identity documents directly — you never need to mail your original passport to the IRS. Nolly.com handles the complete ITIN application process: document certification, Form W-7 preparation, tax return preparation where required, and IRS submission.

Sources

• IRS — Topic No. 857, Individual Taxpayer Identification Number (ITIN)
• IRS — Individual Taxpayer Identification Number
• IRS — How to Apply for an ITIN
• Social Security Administration — Social Security Numbers and Cards
• O&G Tax and Accounting — The ITIN in 2026: Who Qualifies, What’s Allowed, and What’s Restricted

Published May 22, 2026. General information, not tax advice. Nolly Services Inc is a private company and is not part of the IRS.