ITIN vs SSN: What Foreigners Need for U.S. Taxes, Business and Banking (2026)

Key points

• The Social Security Number (SSN) is issued by the Social Security Administration to citizens, green card holders and foreigners authorized to work. It covers work, taxes, credit and social security.
• The Individual Taxpayer Identification Number (ITIN) is issued by the IRS only for tax purposes, to people who need a U.S. tax number but cannot get an SSN.
• An ITIN never authorizes work, gives no social security benefits and grants no immigration status.
• An ITIN is requested with Form W-7, usually attached to a tax return, and expires if it is not used on a federal return for three consecutive years.
• A foreign owner does not need an ITIN or SSN to get an EIN for a U.S. LLC, but often needs an ITIN later to file personal returns or claim treaty benefits.

What is the difference between an ITIN and an SSN?

What is the difference between an ITIN and an SSN? The SSN is the main identification number for people who live and work legally in the United States, issued by the Social Security Administration, and it gives access to employment, social security benefits and credit. The ITIN is a tax-only number issued by the IRS to foreigners and others who must file or be included on a U.S. tax return but are not eligible for an SSN. Anyone eligible for an SSN cannot get an ITIN.

Both numbers have nine digits in the format XXX-XX-XXXX, and an ITIN always begins with 9. They look similar, but they have different issuers, purposes and legal effects.

What is an SSN?

The Social Security Number was created in 1936 to record workers' earnings and contributions to the Social Security system, which pays retirement, disability and survivor benefits. Over time it became the de facto national identifier in the United States, used by employers, banks, landlords, insurers and government agencies.

What the SSN is used for

• Legal employment and payroll reporting on Form W-2.
• Federal and state tax returns.
• Social Security retirement and disability benefits, and Medicare.
• Bank accounts, credit history, loans and credit cards.
• Student aid, driver's licenses, leases and insurance.

Who can get an SSN

• U.S. citizens, usually at birth.
• Lawful permanent residents (green card holders).
• Foreigners with work authorization, such as H-1B, L-1 or J-1 visa holders.
• Students on F-1 or M-1 visas with authorized employment.

Applications use Form SS-5 with a passport, visa, I-94 record and proof of work authorization. Many foreign workers can now request the SSN on their visa or work permit application, and the card is mailed after approval.

What is an ITIN?

The ITIN is a tax processing number. It lets people who are not eligible for an SSN meet their U.S. tax obligations and be identified on tax returns. It is a tax tool only: it does not authorize work, does not give access to Social Security or other benefits and does not change immigration status.

Who needs an ITIN

• Nonresidents with U.S.-source income who must file a return, such as rental income, royalties or business profits, usually on Form 1040-NR.
• Nonresidents claiming a reduced tax rate under a tax treaty.
• Foreign spouses and dependents of U.S. citizens or residents included on a return.
• Resident aliens for tax purposes who are not eligible for an SSN.
• Foreign investors selling U.S. real estate who need to file and recover FIRPTA withholding.
• Foreign owners of U.S. companies who must file personal U.S. returns.

How to apply for an ITIN

The application uses Form W-7 with original or certified copies of identification, usually a passport, and in most cases the federal tax return that requires the number. There are three ways to apply:

• by mail to the IRS in Austin, Texas;
• through an IRS Certifying Acceptance Agent, who can verify passports so the originals do not need to be mailed;
• in person at certain IRS Taxpayer Assistance Centers, by appointment.

Processing usually takes seven weeks and can take eleven or more in peak season. There is no IRS fee for the ITIN itself.

When an ITIN expires

An ITIN expires if it is not used on a federal tax return at least once in three consecutive tax years. Being claimed as a dependent on someone else's return counts as use. An expired ITIN is renewed with a new Form W-7 and the same identification documents, and the IRS recommends renewing well before filing, because a return filed with an expired ITIN can be delayed and lose some credits.

ITIN and SSN for business and investment

Foreign entrepreneurs often assume they need an ITIN to open a U.S. company. They do not. A foreign owner can obtain an Employer Identification Number (EIN) for an LLC or corporation with Form SS-4 without an SSN or ITIN, usually by fax or mail. The ITIN becomes necessary when the owner must file a personal U.S. return, for example because the business has U.S.-effectively connected income, or when a bank, broker or treaty claim requires a personal taxpayer number.

• EIN: identifies the company for taxes, banking and payment platforms.
• ITIN: identifies the foreign owner personally on U.S. returns.
• SSN: needed only if the owner lives and works legally in the United States.

Many U.S. banks and brokers require an SSN or ITIN for personal accounts, while business accounts can often be opened with the company's EIN and the owners' passports. Foreign-owned single-member LLCs must also file Form 5472 each year even when no tax is due. Our comparison of the best countries to open an offshore company explains when a Delaware or Wyoming LLC makes sense.

Legal cautions

• Using an ITIN to work is not allowed and can cause immigration problems.
• Filing returns with wrong data can lead to penalties and a blocked number.
• The SSN is one of the main targets of identity theft; do not share it by email or phone and monitor your credit reports.
• An ITIN does not provide legal status, although a record of tax compliance can help in later visa or residence applications.

Bottom line

The SSN is the key number for anyone who lives and works legally in the United States; the ITIN is a tax-only number for foreigners and others who must deal with the IRS but cannot get an SSN. If your goal is to work and live in the United States, you need an SSN. If your goal is to invest, own a U.S. company or file U.S. taxes from abroad, the EIN and, when required, the ITIN are the right tools. Americans living abroad, by contrast, keep their SSN and their filing duties; see our FBAR guide.

Our Private Advisory Session sets up your U.S. company, tax numbers and bank accounts in the right order and keeps the filings in place.

Sources

• IRS: Individual Taxpayer Identification Number (ITIN)
• IRS: About Form W-7
• IRS: Expired ITIN and renewal
• IRS: About Form SS-4 (EIN application)
• Social Security Administration: Social Security number and card