Your Taxpayer Identification Number is almost certainly on a document you already own. A Social Security Number sits on your Social Security card, every W-2, and any past Form 1040. An Employer Identification Number appears on the IRS confirmation letter (Notice CP 575) mailed when the number was assigned, and on the business returns and bank records that followed. An Individual Taxpayer Identification Number is printed on the CP 565 assignment notice the IRS sent to the address on your Form W-7. If none of that is within reach, each number has its own recovery route through either the Social Security Administration or the IRS, and the right route depends on which TIN you need.
Which TIN Applies to You
Federal law requires everyone who files a return, or who is listed on someone else’s return, to include the correct identifying number.1Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers The IRS recognizes five kinds:
- Social Security Number (SSN), the default TIN for U.S. citizens, permanent residents, and certain temporary workers.
- Employer Identification Number (EIN), assigned to businesses, trusts, estates, and other entities that file returns or employ workers.
- Individual Taxpayer Identification Number (ITIN), issued to people who must file a U.S. return but are not eligible for an SSN.
- Adoption Taxpayer Identification Number (ATIN), a temporary number for a child in a pending adoption when the adoptive parents cannot yet obtain an SSN for the child.
- Preparer Tax Identification Number (PTIN), required for anyone who prepares federal returns for pay.2Internal Revenue Service. PTIN Requirements for Tax Return Preparers
Finding Your Social Security Number
The card itself is the most direct source. If it is filed away at home, that is the fastest answer. Your SSN is also printed on every W-2 an employer has issued you, on any Form 1040 you have previously filed, and on most financial account applications on file with your bank or brokerage. Many statements now mask all but the last four digits, so the full number is more likely to appear on original account-opening paperwork than on a recent statement.
Requesting a Replacement Card
When no document with the full number is available, the Social Security Administration issues replacement cards for free.3Social Security Administration. Replace Social Security Card You can apply online through a my Social Security account, mail in a completed Form SS-5, or apply in person at a local SSA office. Proof of identity is required, and for a first-time card you will also need to prove citizenship or immigration status. The SSA does not release Social Security Numbers over the phone, so one of those three channels is your only option.
There is a hard cap on replacements: three cards per year and ten over a lifetime.4Social Security Administration. Code of Federal Regulations 422-0103 Legal name changes and some other exceptions do not count against the ten-card lifetime limit.
If You Live Outside the United States
U.S. citizens overseas can apply for a first-time or replacement card at a Federal Benefits Unit located inside designated U.S. embassies and consulates, by appointment scheduled via email or phone. Anyone age twelve or older applying for a first-time SSN must appear in person for an interview; replacement card requests can be handled by mail.5Social Security Administration. Joint Frequently Asked Questions on Obtaining Social Security Numbers A Federal Benefits Unit can also confirm whether an SSN already exists on file when you bring proper identification.
Finding Your Employer Identification Number
Start with the EIN confirmation letter, Notice CP 575, that the IRS mailed when the number was first assigned. For an established business, the EIN also appears on previously filed returns such as Form 1120, Form 1065, or Form 941, and on business bank account records. A quick call to your bank’s business banking line often surfaces the number faster than searching through paper files.
If those routes fail, there are two IRS options. You can request an entity transcript through the IRS’s online business account, which displays the EIN. Or you 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) and ask for a confirmation known as Letter 147C. The caller must be someone authorized to act for the entity, such as a sole proprietor, partner, corporate officer, or trustee, and will need to verify the business name, address, entity type, and the responsible party’s SSN or ITIN.6Internal Revenue Service. Employer Identification Number
Finding Your Individual Taxpayer Identification Number
When the IRS approves a new ITIN application, it mails an assignment notice, CP 565, to the address listed on the Form W-7. That letter is the primary proof of the number. The ITIN also appears on any Form 1040 you have previously filed and on other official IRS correspondence sent to your address.
If the letter and past returns are gone, call the IRS Taxpayer Assistance Line at 800-829-1040. Have your full name, date of birth, current mailing address, and information from a recent filing ready. The IRS can confirm the ITIN by phone once it verifies your identity.
One boundary worth knowing: an ITIN expires automatically if it is not included on a U.S. federal tax return for three consecutive tax years, with the expiration falling on December 31 after that third year of non-use.7Internal Revenue Service. How to Renew an ITIN An expired ITIN can still appear on information documents like a Form 1099, but it cannot be used on a return until it has been renewed with a completed Form W-7 (renewal box checked), a U.S. federal tax return, and original or agency-certified identity documents.8Internal Revenue Service. Instructions for Form W-7 Locating the number and being able to use it are two different problems.
Finding Your Adoption Taxpayer Identification Number
The IRS issues an ATIN assignment notice, CP 279, when it approves the application. Check that letter first, then look at any tax return where the child was claimed as a dependent during the adoption process.
If neither document is available, call the IRS Taxpayer Assistance Line at 800-829-1040 with the adoptive parent’s name and SSN, the child’s name and date of birth, and details about the placement. An ATIN is temporary. The IRS deactivates it automatically two years after issuance, and once the adoption is finalized you must obtain a regular SSN for the child and notify the IRS of the new number.
Finding Your Preparer Tax Identification Number
Anyone who prepares federal tax returns for compensation must hold a valid PTIN before working on a return.2Internal Revenue Service. PTIN Requirements for Tax Return Preparers If you already have one but can’t remember the digits, log in to your online PTIN account on the IRS website. The number appears on the right side of the screen once you are signed in.9Internal Revenue Service. Frequently Asked Questions – PTIN Application and Renewal Assistance
Forgotten login credentials are the usual roadblock. The “Forgot User ID” link on the login page emails the user ID (most preparers set their email address as the default), and the “Forgot Password” link sends a reset link that expires after twelve hours. If the email address tied to the account is no longer accessible, call the PTIN Information Line at 877-613-7846, Monday through Friday, 8:00 a.m. to 5:00 p.m. Central time.9Internal Revenue Service. Frequently Asked Questions – PTIN Application and Renewal Assistance
What Happens If You File Without the Right TIN
Not supplying a valid TIN to a payer that reports on Form 1099 triggers backup withholding: the payer must withhold 24 percent of the payment and send it to the IRS.10Internal Revenue Service. Backup Withholding It applies broadly to interest, dividends, independent contractor payments, rents, royalties, and many other income types. You get credit for the withheld amount when you file your return, but until then nearly a quarter of every payment is sitting with the IRS instead of in your account. That is usually enough reason to track the number down before the next 1099 is issued rather than after.