The IRS number is your unique identifier with the U.S. tax system

The IRS number is a nine-digit code that the Internal Revenue Service assigns to you for tax purposes. Most people know it as a Social Security Number (SSN), which serves as your IRS number if you are a U.S. citizen or permanent resident. If you do not have an SSN, the IRS issues an Individual Taxpayer Identification Number (ITIN) instead, which works the same way for filing taxes and reporting income.

Your IRS number is how the government tracks your income, tax payments, refunds, and tax history. Employers, banks, and other organizations report earnings and financial activity to the IRS using this number. When you file a tax return, you enter your IRS number so the IRS can match your return to your existing records.

The IRS number is not something you request or "get" from the IRS in most cases — the Social Security Administration issues SSNs to U.S. citizens and may be able to access immigrants, usually at birth or when you first enter the country. If you need an ITIN because you do not have an SSN, you request one directly from the IRS.

Key Takeaways

  • Your Social Security Number is your IRS number if you are a U.S. citizen or permanent resident; noncitizens may receive an Individual Taxpayer Identification Number instead.
  • The IRS uses your number to track income, tax payments, refunds, and your complete tax history across all years you have filed.
  • Employers and financial institutions report earnings and account activity to the IRS using your IRS number.
  • You do not request an SSN from the IRS — the Social Security Administration issues it; the IRS issues ITINs to those who need them.

Social Security Number versus ITIN

A Social Security Number is issued by the Social Security Administration to U.S. citizens, permanent residents, and certain temporary visa holders. It is a nine-digit number that begins with a three-digit area number. If you were born in the United States or became a permanent resident, you almost certainly have an SSN, and that is your IRS number.

An Individual Taxpayer Identification Number (ITIN) is issued by the IRS to noncitizens who need to file taxes or report income but do not have an SSN. An ITIN also has nine digits and looks similar to an SSN, but it is used only for tax purposes. You cannot use an ITIN to work legally in the United States or to receive Social Security benefits. If you are a noncitizen and need to file taxes, you request an ITIN from the IRS on Form W-7.

Both numbers function identically in the tax system — employers report wages using either one, and you enter whichever number you have when you file your return. The IRS treats both as your tax identification number.

Where to find your IRS number

Your Social Security Number appears on your Social Security card, which you should have received in the mail. If you have lost your card or never received one, you can request a replacement from the Social Security Administration at ssa.gov or by visiting a local Social Security office.

Your SSN also appears on tax documents you have already filed, including past tax returns, W-2 forms from employers, and 1099 forms for other income. If you cannot locate your card, any of these documents will show your number.

If you have an ITIN, it appears on the IRS notice you received when the ITIN was issued. That notice is typically Form W-7 with an attached letter from the IRS. If you have lost that letter, you can contact the IRS at 1-800-829-1040 to request a transcript or verification of your ITIN.

Why the IRS needs your number

The IRS uses your number to match income reports from employers and financial institutions to your tax return. When your employer files a W-2, they report your wages under your IRS number. When a bank reports interest you earned, they use your number. When you file your return, the IRS compares what you reported to what was already reported about you — if the numbers do not match, the IRS may send you a notice or hold your refund.

Your IRS number also links to your tax history. The IRS can see every year you filed, how much you owed or were owed, whether you paid on time, and whether you have any unpaid tax debt. This history affects whether you can receive a refund, whether the IRS will offset your refund against other federal debts, and whether you face penalties or interest.

Financial institutions and government agencies also use your IRS number to verify your identity and check your tax compliance. If you apply for a mortgage, a lender may request your tax returns to verify your income. If you owe child support or student loans, the government may intercept your tax refund using your IRS number to locate it.

What happens if you do not have an IRS number

If you are a U.S. citizen or permanent resident and do not have an SSN, you need to request one from the Social Security Administration. You can apply in person at a local Social Security office or by mail. 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.

If you are a noncitizen and need to file taxes, you must request an ITIN from the IRS. You submit Form W-7 along with required documents that prove your identity and foreign status. You can mail the form and documents to the IRS, or in some cases you can apply in person at an IRS office or through an authorized IRS partner. Processing usually takes four to six weeks.

Without an IRS number, you cannot file a tax return, claim a refund, or report income to the government. Employers cannot legally hire you without an SSN. If you are self-employed or have other income, you still must report it, and you cannot do so without an IRS number.

Protecting your IRS number

Your IRS number is sensitive information. Anyone with your number can file a fraudulent tax return in your name, claim a false refund, or use it to open accounts or take out loans. Treat your IRS number the same way you treat your password — do not share it unless you are certain the person or organization is legitimate.

The IRS will never ask for your number by email, text, or unsolicited phone call. If someone contacts you claiming to be from the IRS and asks for your number, do not provide it. Legitimate IRS contact usually comes by mail, and the IRS will already have your number on file.

If you believe your IRS number has been stolen or misused, contact the IRS at 1-800-829-1040 or visit irs.gov to report identity theft. You can also file a report with the Federal Trade Commission at identitytheft.gov.

Frequently Asked Questions

Is my Social Security Number the same as my IRS number?

Yes, if you are a U.S. citizen or permanent resident. Your Social Security Number is your IRS number. If you do not have an SSN, the IRS issues you an Individual Taxpayer Identification Number, which serves as your IRS number instead.

Can I get a new IRS number if I want to?

No. Your IRS number is permanent and tied to your tax history. The IRS does not issue new numbers except in rare cases of identity theft. If your number has been compromised, contact the IRS to report it, but you will keep the same number.

Do I need an IRS number if I do not work?

If you have no income and file no taxes, you do not need an IRS number for tax purposes. However, if you have any income — even from interest, dividends, or self-employment — you must report it and therefore need an IRS number to file.

What if I lost my Social Security card?

You can request a replacement card from the Social Security Administration at ssa.gov or at a local Social Security office. You do not need the card itself to file taxes or work — you only need to know your number. Your number appears on past tax returns, W-2 forms, and other tax documents.

How long does it take to get an ITIN?

Processing time for an ITIN is usually four to six weeks when you mail Form W-7 to the IRS. If you apply in person at an IRS office or through an authorized partner, you may receive your number faster. Check irs.gov for the current processing time and nearest IRS office.