To find your tax ID number, start with the document that first assigned it: your Social Security card for an SSN, IRS Notice CP 575 for an EIN, or IRS Letter CP 565 for an ITIN. If that document is gone, the same nine-digit number appears on prior tax returns and on most forms and statements tied to your income. When nothing on paper turns it up, the Social Security Administration or the IRS can look it up after verifying your identity. Which route works depends on which type of taxpayer identification number you hold.
Finding Your Social Security Number
The Social Security Number is the tax ID for U.S. citizens and eligible noncitizens, and it shows up in more places than any other TIN.1Social Security Administration. Request Social Security Number for the First Time The physical card is the fastest source. After that, check:
- Any prior-year Form W-2, near the top of the wage statement
- Your Form 1040 individual income tax return
- Form 1099-INT, 1099-DIV, and similar information returns from banks and brokerages
- Annual benefit statements from the Social Security Administration
Using a my Social Security Account
A free my Social Security account at ssa.gov gives you digital access to benefit statements and earnings history, both of which display your SSN.2Social Security Administration. Go Digital! Create Your Personal my Social Security Account Today You don’t need to be receiving benefits to open one. Setting it up takes a few minutes and an identity check, and it’s the cleanest way to keep the number reachable without paper.
Getting a Replacement Card
If every document is gone, a replacement Social Security card is free. In many states you can apply entirely online through ssa.gov; otherwise you’ll book an appointment at a local Social Security office.3Social Security Administration. Replace Social Security Card The SSA asks for proof of identity, and proof of citizenship if it isn’t already on file.4Social Security Administration. Learn What Documents You Need for a Social Security Card The card arrives by mail in five to ten business days.
One limit worth knowing: the SSA caps replacements at three per year and ten per lifetime. Name changes and immigration-status updates that alter the card’s legend don’t count against those limits, and the SSA can grant hardship exceptions.5Social Security Administration. Code of Federal Regulations 422-0103 – Social Security Numbers
Finding Your Employer Identification Number
An EIN is the nine-digit TIN the IRS assigns to businesses, trusts, estates, and certain other entities.6Internal Revenue Service. Understanding Your EIN Once assigned, it’s permanent. The IRS never reassigns it, even after a business closes.7Internal Revenue Service. If You No Longer Need Your EIN
Look first for IRS Notice CP 575, the confirmation letter mailed once when the EIN was first issued. The IRS does not generate duplicates of that notice, so treat the original as a keep-forever document.8Internal Revenue Service. Internal Revenue Service Notice CP 575 G If CP 575 is gone, the number is printed on:
- Every federal business tax return you’ve filed — Form 1120 for corporations, Form 1065 for partnerships, Form 941 for quarterly employment taxes, and similar filings
- Bank statements and loan documents tied to the entity
- State and local business licenses
Calling the IRS for a 147C Letter
When no record surfaces, call the IRS Business and Specialty Tax Line at 800-829-4933.9Internal Revenue Service. Telephone Assistance Contacts for Business Customers Only an authorized person, such as a sole proprietor, corporate officer, or partner, can request the number, and the agent will verify identity and authority by confirming the business name, address, and who originally signed the EIN application.
Ask the agent to send Letter 147C, the official EIN verification letter. It replaces CP 575 for practical purposes and can be faxed or mailed.10Internal Revenue Service. Employer Identification Number Banks and state agencies routinely accept it. The IRS will not confirm an EIN by email or through its public website.
Finding Your Individual Taxpayer Identification Number
An ITIN is the nine-digit number the IRS issues to people who must file a U.S. tax return but don’t qualify for an SSN. It always starts with a 9. Resident aliens, nonresident aliens, and their spouses and dependents can apply regardless of immigration status.11Internal Revenue Service. Individual Taxpayer Identification Number
The most reliable record is IRS Letter CP 565, the assignment notice mailed after your Form W-7 was processed.12Internal Revenue Service. Understanding Your CP565 Notice If that notice is lost, pull any federal tax return you’ve filed. The ITIN appears on Form 1040, Form 1040-NR, or whichever return you used.
There’s no online portal for retrieving an ITIN. Your option is to call the IRS at 1-800-829-1040, where an agent can look up the number after verifying your identity.13USAGov. Get an Individual Taxpayer Identification Number (ITIN) to File Your Tax Return
Check Whether Your ITIN Is Still Active
Finding your ITIN isn’t much use if it has expired. An ITIN that isn’t used on a federal tax return for three consecutive tax years expires on December 31 of that third year. Filing with an expired ITIN can delay your refund, block certain credits, and trigger penalties or interest.14Internal Revenue Service. How to Renew an ITIN Renewal uses the same Form W-7 as the original application, and you’ll resubmit identification documents.15Internal Revenue Service. About Form W-7, Application for IRS Individual Taxpayer Identification Number If you haven’t filed in a few years, check the status before you plan to file again.
Other TINs You Might Be Looking For
Two narrower numbers use the same nine-digit format.16Internal Revenue Service. Taxpayer Identification Numbers
An Adoption Taxpayer Identification Number (ATIN) is a temporary number for a child placed in your home for legal adoption who doesn’t yet have an SSN. It’s requested on Form W-7A and stays valid for two years. Once the adoption is complete and the child receives an SSN, the ATIN is deactivated automatically.17Internal Revenue Service. About Form W-7 A, Application for Taxpayer Identification Number for Pending US Adoptions
A Preparer Tax Identification Number (PTIN) is required for anyone who prepares federal tax returns for compensation. If you’ve forgotten yours, log in to your online PTIN account at irs.gov, which is the fastest way to retrieve it. Your PTIN also appears on every return you’ve prepared for a client. The current renewal fee is $18.75.18Internal Revenue Service. PTIN Requirements for Tax Return Preparers
If You Suspect Your TIN Has Been Stolen
Sometimes you go looking for your tax ID because a return got rejected, and the reason is that someone else has already filed under your number. Other signs of tax-related identity theft include IRS notices about wages from an employer you never worked for, a tax transcript you didn’t request, or confirmation of an online tax-preparation account you didn’t open.19Internal Revenue Service. When to File an Identity Theft Affidavit
If any of that describes your situation, file Form 14039, Identity Theft Affidavit, which you can submit to the IRS by mail or fax, or electronically through the Federal Trade Commission’s site. If the IRS has sent you a verification letter like 5071C or 4883C, follow those instructions instead of filing Form 14039. The dedicated IRS line for ongoing identity-theft cases is 800-908-4490.20Internal Revenue Service. Reporting Identity Theft
Anyone with an SSN or ITIN who can verify their identity can also enroll in the IRS Identity Protection PIN program, which issues a fresh six-digit code each year that must appear on your return. Without the correct IP PIN, a return filed under your number is rejected, which is what makes it effective against fraudulent filings.21Internal Revenue Service. Get an Identity Protection PIN You can sign up through the identity-verification tool at irs.gov.