Where to Find Your Tax ID Number

Your Tax ID number (also called an Employer Identification Number or EIN if you own a business, or your Social Security Number if you're an individual) appears on documents you already have. For most people, it's your Social Security Number, which you can find on your Social Security card, tax returns, W-2 forms, or bank statements. If you own a business or operate as a sole proprietor, your EIN is on your business tax returns, business bank statements, or the IRS letter you received when you first registered the business.

The fastest way to locate it is to check last year's tax return — your SSN appears at the top, and an EIN appears on Schedule C or your business return. If you've lost that paperwork, the IRS website and your financial institutions can help you retrieve it without a new process.

Key Takeaways

  • Your Social Security Number is your tax ID if you file as an individual; it appears on your Social Security card, past tax returns, and W-2 forms.
  • An EIN (Employer Identification Number) is your tax ID if you own a business; the IRS issued it when you registered and sent you a letter with the number.
  • The IRS can confirm your EIN by phone at 1-800-829-4933 if you have lost the original letter.
  • Your bank, accountant, or payroll provider can also tell you your tax ID number if you provide proof of identity.

Checking Your Social Security Card and Official Documents

Your Social Security card is printed with your nine-digit SSN in the format XXX-XX-XXXX. If you still have the physical card, the number is right there. If the card is lost or damaged, you can order a replacement from the Social Security Administration by visiting ssa.gov, calling 1-800-772-1213, or visiting a local Social Security office in person.

Your SSN also appears on any W-2 form your employer sent you, any 1099 form from a contractor or client, your state driver's license or ID card (in some states), and any tax return you filed. If you filed taxes last year, your return is the easiest place to look — it's printed at the top of the first page.

Finding an EIN Through IRS Records

If you own a business and need your EIN, start by looking for the IRS letter you received when the number was first issued. This letter, called a Notice of Assignment of Employer Identification Number, contains your EIN and the date it was assigned. Most people keep this in their business files or with their accountant.

If you cannot locate the letter, call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have your Social Security Number, business name, and the address where you registered the business ready. The IRS can confirm your EIN over the phone. You can also visit an IRS office in person, though calling is faster.

Your EIN also appears on any business tax return you filed (Form 1120, 1120-S, 1065, or 1040-C), your business bank statements, and any payroll tax forms you submitted to the IRS.

Retrieving Your Number From Banks and Financial Institutions

Your bank has your tax ID number on file. Call the customer service number on the back of your debit or credit card, or visit a branch in person with a photo ID. Tell them you need to confirm your tax ID number for your account. They can read it to you over the phone or provide it in writing.

If you have a business account, the bank will have your EIN. If you have a personal account, they will have your SSN. This is one of the fastest ways to retrieve the number if you don't have access to your documents.

Getting Help From Your Accountant or Tax Preparer

If you work with a CPA, tax preparer, or bookkeeper, they have your tax ID number in their records. Call their office and ask them to confirm it. They may ask for your date of birth or other identifying information before providing it over the phone.

If you filed taxes through a tax preparation service like H&R Block or TurboTax, you can log into your account on their website to view your past returns, which display your tax ID number. If you don't remember your login, use the "Forgot Password" option on their site.

What to Do If You've Never Received an EIN

If you own a business but have never received an EIN, you may not have registered it with the IRS yet. Sole proprietors can use their Social Security Number as their business tax ID, but many choose to get an EIN for liability and privacy reasons. You can obtain an EIN for free through the IRS website at irs.gov, by phone at 1-800-829-4933, or by mailing Form SS-4 to the IRS.

The online process through the IRS website is the fastest method — you receive your EIN when ready after submission. By phone, you typically receive it the same day. By mail, it takes about four weeks.

Protecting Your Tax ID Number

Once you locate your tax ID number, treat it like sensitive information. Do not share it in emails, texts, or unsecured messages. Provide it only to your employer, financial institutions, the IRS, and trusted tax professionals who need it for legitimate business purposes.

If you believe your SSN or EIN has been compromised or used fraudulently, contact the IRS Identity Theft Hotline at 1-800-908-4490 and file a report with the Federal Trade Commission at identitytheft.gov.

Frequently Asked Questions

What's the difference between a Social Security Number and an EIN?

A Social Security Number is issued to individuals by the Social Security Administration and is used for personal income tax filing and benefits. An EIN is issued by the IRS to businesses, partnerships, and certain other entities. If you're self-employed as a sole proprietor, you can use your SSN as your business tax ID, but many choose to get an EIN instead.

Can I look up someone else's tax ID number?

No. Tax ID numbers are confidential. You cannot look up another person's SSN or EIN through the IRS or any public database. If you need someone's tax ID for a legitimate business purpose, they must provide it to you directly.

What if I lost my Social Security card and need my number right away?

You don't need the physical card to find your number. Check your past tax returns, W-2 forms, bank statements, or driver's license. If none of those are available, call the Social Security Administration at 1-800-772-1213 and they can confirm your number over the phone with proof of identity.

How long does it take to get a new EIN if I've lost mine?

You don't need a new EIN. The IRS keeps permanent records of every EIN issued. Call 1-800-829-4933 with your business information and they will confirm your existing number. A new EIN is only issued if you change your business structure or ownership.

Is my tax ID number the same as my account number with the IRS?

No. Your tax ID number (SSN or EIN) is different from any account number the IRS assigns to your specific tax case. The IRS uses your tax ID to identify you, but they may also assign you a case number for correspondence about a specific tax year or issue.