TIN vs EIN: Key Differences, Uses, and How to Apply

A Taxpayer Identification Number (TIN) is the umbrella category the IRS uses for every tax ID number it tracks, and an Employer Identification Number (EIN) is one specific type of TIN assigned to businesses and other entities. So the TIN vs EIN question is a little misleading: every EIN is already a TIN. The real question is which kind of TIN applies to you, and for most businesses the answer is an EIN.

What a TIN Actually Covers

A TIN is a nine-digit identifier the IRS uses to track individuals and entities for tax purposes.¹ Federal law requires you to include your TIN on tax returns, W-2s, 1099s, and other documents you file or receive.² The IRS recognizes five types:

Social Security Number (SSN), issued by the Social Security Administration to U.S. citizens and certain noncitizens. This is the TIN most people use for employment and personal tax filing.³
Employer Identification Number (EIN), issued by the IRS to businesses, nonprofits, estates, trusts, and other entities.
Individual Taxpayer Identification Number (ITIN), issued by the IRS to people who need to file a federal tax return but aren’t eligible for an SSN. An ITIN does not authorize work in the United States and does not confer Social Security benefits.⁴
Adoption Taxpayer Identification Number (ATIN), a temporary number the IRS assigns to a child being adopted, so adoptive parents can claim the child before the SSN comes through.
Preparer Tax Identification Number (PTIN), issued to anyone who prepares federal returns for compensation. A PTIN is eight digits preceded by the letter “P” rather than the standard nine-digit format.

So when someone says “I need a TIN,” they really mean one of these specific numbers. Which one depends on who they are and what they’re doing.

What an EIN Is

An EIN is a nine-digit number the IRS assigns to identify a business or other entity for tax purposes.⁵ It functions like a Social Security Number for a business. The format is XX-XXXXXXX compared to an SSN’s XXX-XX-XXXX, so the two are easy to tell apart on a form.⁶ Businesses use an EIN to file tax returns, report employee wages, open bank accounts, and apply for licenses.⁷

How the Two Compare in Practice

Because an EIN sits inside the TIN category, the practical comparison is really between an EIN and the two personal TINs most readers encounter: the SSN and the ITIN.

Who gets one. Individuals receive SSNs or ITINs. Businesses, nonprofits, estates, and trusts receive EINs.¹
Who issues it. The Social Security Administration issues SSNs. The IRS issues everything else, including EINs and ITINs.¹
Format. SSNs are XXX-XX-XXXX. EINs are XX-XXXXXXX. ITINs follow the SSN format but always begin with the digit 9.
Expiration. SSNs and EINs never expire. An ITIN expires if it goes unused on a federal return for three consecutive tax years.⁸

Which Personal TIN You Need

You’ll use an SSN or ITIN any time you interact with the federal tax system as an individual. That includes filing a federal income tax return, starting a job, opening a personal bank account, and claiming dependents (each dependent needs their own TIN).¹ Foreign individuals also use a TIN to claim tax treaty benefits.⁹

If you’re a nonresident or resident alien with a U.S. federal tax filing obligation but no eligibility for an SSN, you’ll apply for an ITIN.⁴ One narrow exception: foreign individuals receiving income from marketable securities can claim treaty benefits on Form W-8BEN without a U.S. TIN.⁹

When You Need an EIN

The IRS requires an EIN if any of the following apply:⁷

You have employees.
You operate as a corporation, partnership, or LLC that files its own return.
You withhold taxes on income paid to a nonresident alien.
You file employment, excise, or alcohol, tobacco, and firearms tax returns.
You run a nonprofit organization, estate, trust, or retirement plan.

Even where it isn’t strictly required, you can request an EIN for banking or state tax reasons.⁷

Sole Proprietors and Freelancers

This is where the TIN vs EIN confusion hits hardest. A sole proprietor with no employees and no excise tax obligations can legally use their SSN for all federal tax purposes and skip the EIN entirely. But many freelancers and independent contractors get one anyway. The reason is practical: every W-9 you hand to a client exposes whichever tax ID you put on it. An EIN keeps your SSN out of other people’s filing cabinets and lowers your identity theft exposure.

Single-Member LLCs

A single-member LLC with no employees and no excise tax liability doesn’t technically need its own EIN for federal income tax purposes. The IRS treats it as a disregarded entity and looks through to the owner’s SSN or EIN.¹⁰ But hire even one employee and the LLC must get its own EIN and use it for all employment tax reporting. Most single-member LLCs end up with an EIN regardless, because banks and state agencies ask for one.

How to Apply

SSN

Apply through the Social Security Administration using Form SS-5.¹¹ If you’re in the United States, you can start online and then visit a local SSA office with your documents, or submit everything by mail.³ The card typically arrives within 7 to 10 business days after approval; mail-in applications add two to four weeks of processing before that clock starts.¹²

ITIN

Submit Form W-7 to the IRS by mail, in person at a Taxpayer Assistance Center, or through an IRS-authorized Acceptance Agent.¹³ Processing can take months. As of early 2026, the IRS was processing Form W-7 applications received in February 2026.¹⁴ Build in extra time during peak filing season.

EIN

The IRS offers four application paths, all based on Form SS-4:¹⁵

Online. The fastest option. The IRS’s EIN Assistant walks you through the questions and issues your EIN immediately upon approval. Available only if your principal place of business is in the United States or U.S. territories.¹⁶
Fax. Send a completed paper Form SS-4; you’ll typically have your EIN within five business days.¹⁴
Mail. Allow about 30 days for processing.¹⁴
Phone. Available only to international applicants with no U.S. principal place of business. Call 267-941-1099 (not toll-free), Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern time.¹⁵

EIN Applications Are Free

The IRS does not charge for an EIN. Third-party websites that mimic the look of the IRS site and charge up to $300 for an EIN filing service have drawn enforcement warnings from the Federal Trade Commission.¹⁷ Before you apply online, confirm you’re on irs.gov and not a lookalike.

Watch the ITIN Clock

Only the ITIN has an expiration risk among the three TINs most people use. If you don’t use your ITIN on a federal return for three consecutive tax years, it expires on December 31 of that third year. Filing with an expired ITIN can delay your refund and block certain credits until you renew. Renewal uses the same Form W-7, with the “Renew an existing ITIN” box checked, submitted the same ways as a first-time application. If your legal name has changed since the ITIN was first issued, include documentation such as a marriage certificate or court order.⁸

1
Internal Revenue Service. Taxpayer Identification Numbers (TIN)
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Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers
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Social Security Administration. Request a Social Security Number for the First Time
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Internal Revenue Service. Individual Taxpayer Identification Number (ITIN)
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Internal Revenue Service. Valid EINs
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Internal Revenue Service. Understanding Your EIN
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Internal Revenue Service. Employer Identification Number
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Internal Revenue Service. How to Renew an ITIN
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Internal Revenue Service. U.S. Taxpayer Identification Number Requirement
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Internal Revenue Service. Single Member Limited Liability Companies
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Social Security Administration. Application for Social Security Card Form SS-5
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Social Security Administration. How Long Will It Take to Get a Social Security Card
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Internal Revenue Service. About Form W-7, Application for IRS Individual Taxpayer Identification Number
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Internal Revenue Service. Processing Status for Tax Forms
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Internal Revenue Service. Instructions for Form SS-4
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Internal Revenue Service. Get an Employer Identification Number
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Federal Trade Commission. FTC Warns Operators of Websites That Charge for an Employer Identification Number and Claim Affiliation With the IRS