ITIN vs. SSN vs. EIN in 2026: Which U.S. Taxpayer ID You Actually Need

01The three numbers at a glance

The U.S. tax system runs on taxpayer identification numbers. There are three you'll hear about: the Social Security Number (SSN), the Individual Taxpayer Identification Number (ITIN), and the Employer Identification Number (EIN). All three are nine digits. That's where the similarity ends.

• SSN — issued by the Social Security Administration (SSA). Format XXX-XX-XXXX. For U.S. citizens and work-authorized noncitizens. Authorizes employment. Never expires.
• ITIN — issued by the IRS. Format 9XX-XX-XXXX (always starts with 9). For people who have a U.S. tax obligation but can't get an SSN. Tax reporting only. Can expire.
• EIN — issued by the IRS. Format XX-XXXXXXX. Identifies a business. Permanent.

The quick test: SSN identifies a worker, ITIN identifies a filer, EIN identifies a business. Many immigrant founders end up holding two of these — an ITIN for themselves and an EIN for their company. If that's you, our immigrant money playbook walks through the sequence.

02SSN: the default for citizens and work-authorized people

The SSN is the SSA's identifier for U.S. citizens and noncitizens authorized to work in the United States. It's both your tax ID and your work-authorization proof.

You apply with Form SS-5, the Application for a Social Security Card. It's free — there's no fee to the IRS or SSA. SSNs are typically issued within about two weeks.

One rule trips people up: if you're eligible for an SSN, you must apply for that — not an ITIN. File a W-7 for an ITIN while you qualify for an SSN, and the IRS will reject it.

03ITIN: the tax-only number for people without an SSN

An ITIN looks almost identical to an SSN, but it always starts with a 9: 9XX-XX-XXXX. The IRS issues it to people who have federal tax filing or payment requirements but can't get an SSN — regardless of immigration status.

What the ITIN does not do is just as important: it doesn't authorize work, it doesn't provide Social Security benefits, and it doesn't change your immigration status. It exists so you can pay and file under the Internal Revenue Code.

As of October 2025, the IRS has issued roughly 31 million ITINs since the program began, with about 5 million active today. In 2022, ITIN holders filed 3.8 million returns and contributed $6.5 billion to Social Security and Medicare.

You apply with Form W-7. Processing typically takes 7 to 11 weeks, and up to 120 days during peak season. For the step-by-step, read the complete ITIN filing guide.

04ITIN expiration: the rule that catches people off guard

Unlike an SSN, an ITIN can expire. If it isn't used on a federal tax return for any 3 consecutive tax years, it expires on December 31 after that third year.

There's also a legacy rule: ITINs issued before 2013 with certain middle digits — 88, 90, 91, 92, 94, 95, 96, 97, 98, or 99 — have expired. Any pre-2013 ITIN with middle digits 88 (9XX-88-XXXX) expired at the end of 2025.

If you file with an expired ITIN, the IRS will send an ITIN renewal notice, delay your return, and hold refunds tied to credits like the Child Tax Credit. You can renew by mail, at an IRS Taxpayer Assistance Center, or through an IRS Acceptance Agent. Renewal is free, though you may pay for document certification or translation. The IRS notifies you in about 7 weeks — 9 to 11 weeks if you renew between January 15 and April 30, or from overseas.

05ITIN vs. SSN: you can't hold both

This one matters. A person can have an ITIN or an SSN — never both at the same time.

If you have an ITIN and later become eligible for an SSN (say, you get work authorization), your ITIN is invalidated once you receive the SSN. You should contact the IRS to combine your tax records under your new SSN. Don't keep filing on the old ITIN.

Why care? Because in 2026, several tax breaks now hinge on having an SSN specifically. We'll get to those next.

06EIN: the number for your business

The Employer Identification Number (EIN), also called a Federal Tax ID or FEIN, identifies a business operating in the U.S. It's nine digits but formatted differently — XX-XXXXXXX — so it's easy to tell apart from an SSN or ITIN. An EIN is permanent and does not expire.

Every EIN application names a "responsible party" — a real person who gives their legal name and their own taxpayer ID, which can be an SSN or an ITIN. That's the key for immigrant founders: you can get an EIN for a business using your ITIN as the responsible party's ID.

The IRS online application is fastest and issues the EIN instantly — but non-residents without an SSN can't use the online portal. Instead, international applicants call 267-941-1099 (not toll-free), Monday through Friday, 6:00 a.m. to 11:00 p.m. ET.

Thinking about which entity needs an EIN and when? Our Money Moves Guide covers the order of operations.

07What OBBBA changed for ITIN filers in 2026

The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025 as Public Law 119-21, rewired several credits and deductions to require a work-authorized SSN. This is the biggest shift for ITIN families. You can still file a return — that hasn't changed. But certain benefits are now off the table for ITIN-only filers.

Child Tax Credit — now requires an SSN for the parent

The 2026 Child Tax Credit is $2,200 per qualifying child under 17, with up to $1,700 refundable. OBBBA expanded the SSN requirement to the person claiming the credit. Starting in 2025 and continuing into 2026, at least one taxpayer on the return must hold an SSN valid for employment, issued before the return's due date. On a joint return, at least one spouse needs that SSN. Families where both parents file with ITINs are disqualified — even when the child has an SSN. The child must also have an SSN to be a qualifying child. The Joint Committee on Taxation estimates about 2 million children with SSNs would be denied the CTC under this rule.

Tips, overtime, and senior deductions — SSN required

• No tax on tips: deduct up to $25,000 of qualified tips — but a single filer with only an ITIN can't claim it.
• No tax on overtime: deduct up to $12,500 ($25,000 joint) of qualified overtime, phasing out above $150,000 MAGI ($300,000 joint). Both spouses must have a valid SSN — one ITIN spouse disqualifies the couple.
• Senior deduction: a new $6,000 deduction for those 65+ (2025–2028, phasing out over $75,000 MAGI / $150,000 joint) also requires the claimant to hold a valid SSN.
• Education credits: the American Opportunity and Lifetime Learning credits now require a work-authorized SSN. A student with an ITIN can't claim them, even if a parent has an SSN.

08What ITIN filers can still do

Losing access to some credits doesn't mean ITIN holders stop filing. Filing protects your record, supports future immigration applications, and keeps you compliant.

Want to estimate your number before you file? Run it through our free calculator, then check the details against the complete ITIN filing guide.

2026 figures worth knowing

From IRS Rev. Proc. 2025-32, the 2026 standard deduction is $32,200 (married filing jointly), $16,100 (single), and $24,150 (head of household). The maximum EITC for three or more children is $8,231. OBBBA also permanently kept the individual rate brackets at 10%, 12%, 22%, 24%, 32%, 35%, and 37%, and raised the SALT deduction cap to $40,000.