IRS EIN verification runs through a few different channels depending on whose number you’re checking. For your own EIN, the IRS will confirm it by phone or issue a Letter 147C. For a vendor or contractor, you collect a Form W-9 and can run the name and number through the free IRS TIN Matching Program before filing 1099s. For a non-profit, the IRS publishes a public search tool. Getting verification right before you file matters: an incorrect or missing TIN on a 1099 can cost up to $340 per return for 2026 filings, and $680 per return if the IRS decides you disregarded the rules on purpose.1Internal Revenue Service. Information Return Penalties
Verifying Your Own EIN
The fastest source is the CP 575 notice the IRS mailed when it first assigned the number. That letter shows the EIN next to the exact legal name in the IRS master file, so it also proves the two match.2Internal Revenue Service. Employer Identification Number
Lost the CP 575? Any previously filed federal return will show it. Corporations find it on Form 1120, partnerships on Form 1065, sole proprietors on Schedule C.3Internal Revenue Service. Instructions for Form 1120 (2025) The paperwork from opening your business bank account almost certainly has it too.
The IRS Business Tax Account portal lets sole proprietors, S-corporation shareholders, and C-corporation designated officials view their business profile online after identity verification.4Internal Revenue Service. Business Tax Account Once you’re in, the account displays what the IRS has on file for your entity.
When none of those options 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.5Internal Revenue Service. Telephone Assistance Contacts for Business Customers The agent will ask for the legal business name, registered address, and the name of a principal officer or owner to confirm your authority. If you need written proof, request Letter 147C. The IRS issues it specifically to confirm a previously assigned EIN.2Internal Revenue Service. Employer Identification Number An Entity transcript, requested online or by mail, serves the same purpose.
Verifying a Vendor or Contractor’s EIN
When you hire an independent contractor or vendor you’ll need to issue a 1099 to, the standard verification tool is Form W-9, Request for Taxpayer Identification Number and Certification.6Internal Revenue Service. About Form W-9, Request for Taxpayer Identification Number and Certification The payee fills in their legal name, entity type, and TIN, then signs a certification under penalty of perjury that the information is correct and that they are not subject to backup withholding.7Internal Revenue Service. Instructions for the Requester of Form W-9 (03/2024)
The name on Line 1 has to match the name associated with that TIN in IRS records. A mismatch is one of the most common triggers for a CP2100 notice. Before you accept a W-9, check that the name, entity type, and TIN look consistent. A partnership handing you an SSN instead of an EIN is worth catching immediately.
You don’t send the W-9 to the IRS unless they specifically ask for it during an examination. You keep it as your proof of due diligence. If the IRS later challenges a TIN on one of your information returns, a properly completed W-9 is your primary defense.
The Single-Member LLC Trap
One of the most frequent W-9 errors involves single-member LLCs. The IRS treats a single-member LLC as a “disregarded entity” for income tax purposes, which means the W-9 should list the owner’s name on Line 1 and provide the owner’s SSN or personal EIN, not the LLC’s separate EIN.8Internal Revenue Service. Single Member Limited Liability Companies The LLC’s legal name goes on Line 2 as the business name. When vendors fill this out backwards, the name/TIN combination won’t match IRS records and the 1099 filing gets flagged.
Using the IRS TIN Matching Program
The W-9 relies on the payee telling the truth. The IRS TIN Matching Program lets you confirm that a name and TIN combination actually matches IRS records before you file. The program is free and open to any payer who has filed at least one information return in either of the two prior tax years.9Internal Revenue Service. Taxpayer Identification Number (TIN) Matching Tools Access runs through the IRS e-Services portal after electronic registration and authentication.10Internal Revenue Service. E-Services
Once registered, you have two options.
- Interactive TIN Matching accepts up to 25 name/TIN combinations at a time with immediate results, and up to 999 requests in a 24-hour period.
- Bulk TIN Matching accepts a file with up to 100,000 combinations, with results delivered within 24 hours to a secure mailbox.
The system returns a simple match or non-match for each combination.9Internal Revenue Service. Taxpayer Identification Number (TIN) Matching Tools A match confirms your data. A non-match means you need to go back to the vendor for a corrected W-9. Running matches in the fall, well ahead of the January 1099 deadline, gives you time to chase corrections without a scramble.
Verifying a Non-Profit Organization’s EIN
For tax-exempt organizations, the IRS publishes the Tax Exempt Organization Search at apps.irs.gov.11Internal Revenue Service. Search for Tax Exempt Organizations Look up any non-profit by name or EIN to see its current tax-exempt status, determination letters, and recent Form 990 filings. The Form 990 itself lists the organization’s EIN, legal name, and address, which gives you a secondary confirmation that the number matches the entity in front of you.
The tool pulls from several IRS databases, including Publication 78 data (organizations eligible to receive tax-deductible contributions) and the auto-revocation list (organizations that lost exempt status for failure to file). If a non-profit you’re vetting doesn’t appear, or shows up on the revocation list, flag it before you send money.
Why the Verification Step Is Worth It
The reason for all of this is the penalty structure. For information returns due in 2026, an incorrect or missing TIN is penalized per return, escalating with delay:1Internal Revenue Service. Information Return Penalties
- $60 per return if corrected within 30 days.
- $130 per return if corrected after 30 days but by August 1.
- $340 per return if corrected after August 1 or never filed.
- $680 per return for intentional disregard, with no cap on the total.
Those figures apply separately to the return filed with the IRS and to the payee statement given to the recipient, so a single bad TIN can generate two penalties.1Internal Revenue Service. Information Return Penalties Across a stack of 1099s, the math argues strongly for running TIN Matching before year-end.
When Verification Fails
If a payee refuses to provide a TIN, gives you one that’s obviously wrong, or the IRS notifies you of a mismatch, you’re required to start backup withholding at 24% of each reportable payment.12Internal Revenue Service. Topic No. 307, Backup Withholding The rate is a flat statutory figure and applies regardless of the payment size. Withheld amounts get remitted to the IRS and reported on Form 945.13Internal Revenue Service. About Form 945, Annual Return of Withheld Federal Income Tax
When the IRS identifies a name/TIN mismatch on a return you filed, it sends a CP2100 or CP2100A notice. You then send the payee a First B-Notice requesting a corrected, signed W-9.14Internal Revenue Service. Backup Withholding “B” Program A valid W-9 in response lets you stop backup withholding. No response means you start withholding 24% on future payments.
If the IRS flags the same payee a second time within a three-calendar-year period, you send a Second B-Notice and must immediately begin backup withholding with no grace period.14Internal Revenue Service. Backup Withholding “B” Program The second round is stricter: a fresh W-9 alone won’t resolve it. The payee has to contact the IRS or Social Security Administration directly, and you can’t stop withholding until the IRS confirms the correction. That fallout is exactly the reason to catch mismatches through TIN Matching well before you file.