There is no single government website where you type in your name and get your Taxpayer Identification Number back. How to find your TIN online depends on which number you need: your Social Security Number lives inside your my Social Security account at ssa.gov, your Employer Identification Number can be pulled from your IRS confirmation notice or prior business tax filings, and your Individual Taxpayer Identification Number appears on IRS Notice CP 565 or the prior-year return you filed with it.
Which TIN Are You Looking For
The IRS uses three main Taxpayer Identification Numbers, and each has its own retrieval path.1Internal Revenue Service. Taxpayer Identification Numbers (TIN) A Social Security Number is the nine-digit number issued by the Social Security Administration to citizens and authorized residents. An Employer Identification Number is the nine-digit number the IRS assigns to businesses and other entities.2Internal Revenue Service. Employer Identification Number An Individual Taxpayer Identification Number is a nine-digit number for people who need to file U.S. taxes but don’t qualify for an SSN; it’s for federal tax purposes only.3Internal Revenue Service. Am I Eligible to Apply for an Individual Taxpayer Identification Number Pick the one you need and skip to that section.
Finding Your Social Security Number Online
The closest thing to an online SSN lookup is your personal my Social Security account at ssa.gov. Once you’re signed in, your Social Security Statement shows the number, and the same account lets you request a replacement card, check earnings, and estimate benefits.4Social Security Administration. my Social Security
Setting Up the Account
If you don’t already have an account, you’ll create one through either Login.gov or ID.me. As of June 2025, those are the only two sign-in options for SSA online services, and one is enough.5Social Security Administration. Learn About Changes We’re Making to Your Personal my Social Security Account Both verify identity by asking you to upload a government-issued photo ID and, in some cases, take a selfie or join a short video call to match you to the document.
Verification can take a few minutes or a few days. If one provider rejects you, try the other. People with expired IDs or photos that don’t match cleanly sometimes have better luck with a video call through ID.me.
Places Your SSN Already Appears
Before you sit through account setup, check whether the number is already within reach. Your SSN is printed on your Social Security card, and it also appears on prior-year tax returns (Form 1040), W-2 forms from employers, and 1099 forms. If you’ve used tax software, old returns are usually stored inside that account.
Finding Your EIN Online
The IRS does not offer an online EIN lookup for business owners. There’s no portal where you enter a business name and get the number back. Retrieval online depends on documents and accounts you already have.
Your IRS Confirmation Notice (CP 575)
When the IRS first assigns an EIN, it sends Notice CP 575. If you applied online, you also received an immediate confirmation at the end of the application.6Internal Revenue Service. Get an Employer Identification Number Search your email (if you saved or forwarded the confirmation) and your files for either one. This is the fastest route because the number is unambiguous and official.
Previously Filed Tax Returns
Your EIN is on every federal return the business has filed. Corporations use Form 1120. Partnerships use Form 1065. Employers who’ve run payroll can find it on Form 941 (quarterly payroll tax return) or Form 940 (annual unemployment tax return). If you use accounting software or a payroll service, the EIN is usually stored in the account settings.
Bank and Loan Records
Your business bank account application required the EIN, so account-opening paperwork or online banking records should have it. Loan applications, business licenses, and state registration filings often list it too.
Looking Up Another Organization’s EIN
If the EIN you need belongs to a tax-exempt nonprofit, the IRS offers a free Tax Exempt Organization Search where you can look up organizations by name or EIN.7Internal Revenue Service. Tax Exempt Organization Search For publicly traded companies, EINs appear in 10-K filings and other documents on the SEC’s EDGAR system. These tools only cover organizations that file publicly, so they won’t turn up the EIN of a private LLC or sole proprietorship.
Finding Your ITIN Online
As with the EIN, the IRS has no online tool that returns an ITIN. You retrieve it by tracing documents you already have.
The most reliable source is IRS Notice CP 565, which the IRS mails when it assigns or renews an ITIN.8Internal Revenue Service. Understanding Your CP565 Notice If you’ve misplaced that notice, check any prior-year federal return you filed with the ITIN. It appears at the top of Form 1040 where an SSN would normally go.
You can also access tax transcripts through your IRS online account at irs.gov, but transcripts partially mask personally identifiable information.9Internal Revenue Service. Get Your Tax Records and Transcripts You may see only part of the ITIN, not all nine digits.
If the Online Route Doesn’t Work
When the digital trail runs out, each TIN has an offline fallback.
For an SSN, you can request a replacement Social Security card through ssa.gov if your situation qualifies for online processing, or by visiting a local SSA office.10Social Security Administration. Replace Social Security Card Federal law limits you to three replacement cards a year and ten in a lifetime, though name changes and immigration status changes don’t count toward those limits.11Federal Register. Social Security Number (SSN) Cards – Limiting Replacement Cards Bring a current government-issued photo ID and proof of citizenship or immigration status.
For an EIN, the person listed as the “responsible party” on the original application can call the IRS Business and Specialty Tax Line at 800-829-4933, Monday through Friday, 7 a.m. to 7 p.m. local time (Alaska and Hawaii follow Pacific time).12Internal Revenue Service. Telephone Assistance Contacts for Business Customers The IRS verifies identity and gives the EIN over the phone. Only the responsible party or an authorized representative with a valid power of attorney can receive it. Nominees are not authorized.2Internal Revenue Service. Employer Identification Number
For an ITIN, call the IRS at 800-829-1040. You’ll go through identity verification before they release the number, and hold times are long during tax season. An IRS-authorized Certifying Acceptance Agent is the in-person alternative. These agents can verify identity documents in person or by video and access ITIN information through the IRS.13Internal Revenue Service. ITIN Acceptance Agent Program
If You Find an Old ITIN, Check That It’s Still Valid
ITINs expire. If yours hasn’t been used on a federal return for three consecutive tax years, it expires on December 31 of that third year.14Internal Revenue Service. How to Renew an ITIN This trips up people who skip filing for a few years and then discover the number they finally tracked down no longer works.
To renew, submit Form W-7 with documents proving identity and foreign status. A valid passport is the simplest option because it covers both. Without a passport, you’ll need at least two documents from the IRS’s approved list, and at least one must include a photograph. All documents must be originals or certified copies from the issuing agency, and none can be expired.15Internal Revenue Service. Instructions for Form W-7 A Certifying Acceptance Agent can authenticate most documents so you don’t have to mail originals, which matters if your passport or national ID is something you can’t be without for weeks.13Internal Revenue Service. ITIN Acceptance Agent Program