To check or verify a TIN number online, the tool you use depends on whose number it is. For your own Social Security Number or ITIN, sign in to the IRS Online Account at irs.gov and pull a transcript. For a contractor or vendor’s number before you file a 1099, register for the IRS TIN Matching program through e-Services and submit the name-and-TIN combination there. For a publicly traded company’s EIN, search SEC EDGAR; for a nonprofit’s EIN, use the IRS Tax Exempt Organization Search. Private-company EINs are protected return information and have no public lookup.
Figure Out Which TIN You’re Checking
The IRS issues several kinds of Taxpayer Identification Numbers, and the right tool depends on the type. A Social Security Number identifies U.S. citizens and permanent residents. An Employer Identification Number identifies a business entity. An Individual Taxpayer Identification Number is issued to people who must file a U.S. return but aren’t eligible for an SSN.1Internal Revenue Service. Taxpayer Identification Numbers (TIN) Once you know which one you’re after, the online path is straightforward.
Check Your Own SSN or ITIN Online
The IRS Online Account at irs.gov is the fastest way to confirm the number on file for you personally. You’ll need to verify your identity through a third-party service during signup, so keep a government-issued photo ID within reach.2Internal Revenue Service. Online Account for Individuals
Once you’re in, you can view tax records and pull transcripts that show the identifying number tied to your account. One thing to know before you look: the IRS partially masks SSNs and other personal information on transcripts to protect against identity theft. You’ll see enough digits to confirm the number, not the full unredacted string.3Internal Revenue Service. Online Account and Tax Transcripts Can Help Taxpayers File a Complete and Accurate Tax Return
ITIN holders use the same portal. Keep in mind that an ITIN not used on a federal return for three consecutive years expires on December 31 of that third year. If yours has expired and you need it on an upcoming return, renew by submitting Form W-7 by mail or in person; an expired ITIN can still be used on information returns like a 1099 reporting payments you receive.4Internal Revenue Service. How to Renew an ITIN Allow about seven weeks for a W-7 response, or nine to eleven weeks during peak filing season (January 15 through April 30) and for overseas applications.5Internal Revenue Service. Individual Taxpayer Identification Number (ITIN)
Recover Your Own EIN
There is no online portal where a business owner types in a company name and gets back the EIN. That surprises a lot of people, especially those who applied years ago and never saved the confirmation. What the IRS suggests instead: check the CP 575 confirmation notice issued when you originally applied, look at previous business tax returns, or contact the bank where your business account is held. If none of those work, call the IRS Business and Specialty Tax Line at 800-829-4933, Monday through Friday, 7 a.m. to 7 p.m. local time. An agent will verify your identity and provide the number over the phone if you’re authorized to receive it.6Internal Revenue Service. Employer Identification Number
For a formal written record, request Letter 147C, which verifies your previously assigned EIN, or pull an entity transcript through the IRS website.6Internal Revenue Service. Employer Identification Number
Verify a Payee’s TIN Through IRS TIN Matching
If you pay contractors, freelancers, or other parties who receive 1099s, the IRS TIN Matching program lets you verify each payee’s name-and-TIN combination against IRS records before you file. This is the online verification tool most businesses actually need, and catching mismatches here avoids CP2100 notices and backup withholding later.
To use it, you have to be a payer listed on the IRS Payer Account File database and register through the IRS e-Services portal at irs.gov.7Internal Revenue Service. Taxpayer Identification Number (TIN) Matching Each person in your organization who needs access registers separately.8Internal Revenue Service. E-Services Registration
Collect the payee’s information on Form W-9, which asks for the legal name, TIN, and a certification that the information is correct.9Internal Revenue Service. Instructions for the Requester of Form W-9 The legal name matters. For businesses, the IRS derives a “name control” from the first four characters of the entity name, and the name-and-TIN pair has to match that record or the submission rejects.10Internal Revenue Service. Using the Correct Name Control in E-Filing Corporate Tax Returns Small differences in punctuation or spacing can throw a false mismatch.
Two modes are available. The interactive option verifies up to 25 combinations per session with instant results. The bulk option accepts up to 100,000 combinations in one upload, with results back within 24 hours.11Internal Revenue Service. Taxpayer Identification Number (TIN) Matching Tools Results land in a secure mailbox inside the e-Services portal.12Internal Revenue Service. E-Services
Reading the Response Codes
Every submission comes back with a single-digit code:
- Code 0 means the name and TIN match IRS records. Nothing more to do.
- Code 1 means the TIN was missing or wasn’t nine digits. Re-enter and resubmit.
- Code 2 means the TIN isn’t currently issued by the IRS or SSA. The payee may have given you an old or invalid number.
- Code 3 means the name and TIN don’t match. This is the substantive mismatch that triggers real follow-up: go back to the payee for a corrected W-9.
- Code 4 means the request itself was invalid, usually a formatting error.
Look Up Another Business’s EIN Online
Publicly Traded Companies: SEC EDGAR
Public companies disclose their EIN on the cover page of the annual Form 10-K they file with the Securities and Exchange Commission.13U.S. Securities and Exchange Commission. Form 10-K Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 The SEC’s EDGAR database offers free full-text search of electronic filings going back to 2001. Search by company name or ticker, filter to 10-K filings, and read the cover page for the “I.R.S. Employer Identification No.” field.14Investor.gov. Form 10-K
Nonprofits: IRS Tax Exempt Organization Search
The IRS Tax Exempt Organization Search tool lets you search by organization name or EIN and returns information from several databases, including the list of organizations eligible to receive tax-deductible contributions and copies of Form 990 returns.15Internal Revenue Service. Search for Tax Exempt Organizations Since nonprofits must make Form 990 available to the public, this is a reliable way to confirm both the EIN and the organization’s tax-exempt status.
Private Companies
Private-company EINs are the hardest to find, and often you can’t. Most Secretary of State offices maintain online business entity databases where you can search by name and see registration details, officers, and filing history. Some display the federal EIN; many don’t. When one is shown, it may be outdated.
This is a legal limitation, not a gap in the tools. Federal law treats taxpayer identification numbers as protected return information. Unauthorized disclosure of a TIN is a felony carrying up to five years in prison and a $5,000 fine, and federal employees who are convicted must be terminated. The same penalties apply to anyone who receives a TIN through unauthorized disclosure and publishes it. There is no general public directory of EINs for private businesses. If you need one for a legitimate business purpose, request a W-9 directly from the company.9Internal Revenue Service. Instructions for the Requester of Form W-9
Foreign Payees Use a Different Form
Form W-9 and the TIN Matching program don’t apply to payees outside the United States. Foreign individuals provide Form W-8BEN, and foreign entities use Form W-8BEN-E, to document status and claim any applicable treaty benefits.16Internal Revenue Service. Instructions for Form W-8BEN
Whether a U.S. TIN is required depends on the situation. A foreign individual who is a partner in a U.S. partnership conducting business here must obtain an ITIN and include it on the W-8BEN. The same requirement applies when claiming an exemption for certain annuities under qualified plans. For treaty benefit claims, a foreign payee can generally provide either a U.S. ITIN or a foreign tax identification number issued by their home country. An ITIN is not required for treaty benefits on dividends and interest from publicly traded securities or mutual fund distributions. Foreign payees who hold financial accounts at U.S. institutions and receive U.S.-source income reported on Form 1042-S generally must provide their foreign tax ID on line 6a of the W-8BEN, unless their country of residence doesn’t issue such numbers.16Internal Revenue Service. Instructions for Form W-8BEN A missing or incorrect TIN on a W-8BEN can push withholding to the full 30% statutory rate instead of a reduced treaty rate.
What Happens if a Payee’s TIN Doesn’t Match
If you file information returns with incorrect TINs, the IRS sends a CP2100 or CP2100A notice listing the mismatched accounts. That kicks off the “B-Notice” process.17Internal Revenue Service. Understanding Your CP2100 or CP2100A Notice First, compare the notice against your records. If it doesn’t match what you filed, correct your records internally without contacting the IRS. If it does match, send the payee a B-notice right away.
The documentation escalates each round. A first B-notice can be cleared with a corrected, signed W-9 from the payee. A second B-notice requires more: a copy of the payee’s Social Security card for SSNs, or Letter 147C from the IRS verifying the name and EIN for entities.18Internal Revenue Service. Backup Withholding “B” Program
If the payee doesn’t respond, you must begin backup withholding no later than 30 business days after receiving the CP2100 or CP2100A notice, at a rate of 24% on reportable payments. Once the payee sends a corrected TIN, stop withholding within 30 calendar days.17Internal Revenue Service. Understanding Your CP2100 or CP2100A Notice19Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide Note the asymmetry: the start deadline runs in business days, the stop deadline in calendar days. Running TIN Matching before you file is the cleanest way to keep this whole chain from starting.