What a Tax Identification Number Is

A Tax Identification Number (TIN) is a nine-digit code the Internal Revenue Service (IRS) uses to identify you for tax purposes. It appears on tax forms, W-2s, 1099s, and any document you file with the IRS. The number itself looks like this: XX-XXXXXXX, with hyphens after the first two digits.

The most common type of TIN is a Social Security Number (SSN), which you get from the Social Security Administration. If you do not have an SSN — because you are not a U.S. citizen or permanent resident, for example — the IRS can issue you an Individual Taxpayer Identification Number (ITIN) instead. Businesses, trusts, and estates use an Employer Identification Number (EIN), which serves the same purpose but is issued to entities rather than individuals.

Key Takeaways

  • A Tax Identification Number is a nine-digit code the IRS uses to track your tax records and income.
  • Most people use their Social Security Number as their TIN, but non-citizens can get an ITIN from the IRS.
  • You need a TIN to file taxes, open a bank account, get a job, or claim certain tax credits and deductions.
  • If you lose your TIN or forget it, you can find it on past tax returns, W-2s, or by contacting the IRS directly.

The Three Main Types of Tax Identification Numbers

Social Security Numbers (SSN) are issued by the Social Security Administration to U.S. citizens, permanent residents, and certain temporary visa holders. If you have an SSN, that is your TIN. You receive an SSN at birth or when you first become authorized to work in the United States. The number stays with you for life and does not change.

Individual Taxpayer Identification Numbers (ITIN) are issued by the IRS to people who are not may be able to access for an SSN but need to file taxes or report income. This includes nonresident aliens, undocumented immigrants, and some visa holders. An ITIN looks identical to an SSN (nine digits with hyphens) but is used only for tax purposes. You cannot use an ITIN to work legally or to receive Social Security benefits.

Employer Identification Numbers (EIN) are nine-digit codes issued to businesses, nonprofits, trusts, estates, and other entities. If you are self-employed as a sole proprietor, you typically use your SSN or ITIN instead. An EIN is required if you hire employees, operate as a partnership or corporation, or run certain types of businesses.

When You Need to Provide Your Tax Identification Number

You will need to provide your TIN in several situations. When you start a job, your employer asks for your SSN or ITIN on the W-4 form so they can report your wages to the IRS. When you open a bank account, savings account, or investment account, the bank requests your TIN to report interest and dividends. If you receive income from sources other than an employer — such as freelance work, rental income, or investment returns — that payer will ask for your TIN to issue a 1099 form.

You also provide your TIN when you file your annual tax return. If you claim dependents, apply for tax credits like the Earned Income Tax Credit (EITC) or Child Tax Credit, or deduct mortgage interest or student loan interest, the IRS uses your TIN to verify your records and prevent fraud.

How to Find Your Tax Identification Number

If you know you have a TIN but cannot remember the number, several documents will show it. Check a recent tax return — your TIN appears at the top of Form 1040 or any return you filed. Look at a W-2 from your employer or a 1099 from a client or financial institution. Bank statements and investment account statements also display your TIN. If you have a Social Security card, your SSN is printed on it.

If you cannot locate your TIN through these documents, contact the IRS directly. You can call the IRS at 1-800-829-1040 (the main tax line) and speak to a representative who can verify your identity and provide your number. Have your name, date of birth, and current address ready. The IRS may also ask for other identifying information to confirm who you are before releasing the number.

Getting a Tax Identification Number If You Do Not Have One

If you are a U.S. citizen or permanent resident and do not have an SSN, contact your local Social Security Administration office or visit ssa.gov. You will need to provide proof of citizenship or permanent residency, proof of identity, and proof of age. Processing typically takes one to two weeks, though you may receive a temporary number immediately in some cases.

If you are not may be able to access for an SSN but need to file taxes or report income, you can request an ITIN from the IRS. You submit Form W-7 (Application for IRS Individual Taxpayer Identification Number) along with your tax return or separately. You must provide proof of identity and proof of foreign status. The IRS processes ITIN applications within two to four weeks during tax season and faster during the off-season. You can submit Form W-7 by mail or in person at an IRS office or authorized acceptance agent.

What Happens If Your Tax Identification Number Is Compromised

If you believe your TIN has been stolen or misused — for example, someone filed a tax return using your number or opened accounts in your name — contact the IRS immediately. Call the IRS Identity Theft Hotline at 1-800-908-4490. You can also file Form 14039 (Identity Theft Affidavit) with the IRS to report the theft and request an investigation.

Additionally, place a fraud alert with the three major credit bureaus (Equifax, Experian, and TransUnion) by contacting any one of them. A fraud alert tells creditors to verify your identity before opening new accounts in your name. You can also request a free credit report from each bureau at annualcreditreport.com to check for unauthorized accounts or inquiries. If you find fraudulent activity, file a report with the Federal Trade Commission at identitytheft.gov.

Frequently Asked Questions

Is my Social Security Number the same as my Tax Identification Number?

Yes, if you have a Social Security Number, that is your Tax Identification Number. The IRS uses your SSN to identify you on all tax documents and records. They are the same nine-digit number.

Can I get a new Tax Identification Number if I want to change mine?

No. Your SSN or ITIN does not change during your lifetime. The IRS does not issue replacement numbers for privacy or preference reasons. If your number has been compromised, you report the theft to the IRS and credit bureaus, but you keep the same number.

Do I need a Tax Identification Number to file taxes if I had no income?

If you had no income and are not claimed as a dependent, you typically do not need to file a tax return. However, if someone else claims you as a dependent, you still need a TIN so they can report you on their return. Check the IRS filing requirements for your specific situation.

What is the difference between an ITIN and an SSN?

An ITIN is for tax purposes only and does not authorize work or provide Social Security benefits. An SSN authorizes you to work legally in the United States and qualifies you for Social Security retirement, disability, and survivor benefits. Both are nine-digit numbers formatted the same way.

How long does it take to get a Tax Identification Number?

An SSN typically takes one to two weeks from the Social Security Administration. An ITIN takes two to four weeks during tax season (January through April) and faster during the off-season. Processing times vary depending on whether you submit by mail or in person.