IRS TIN Matching: How It Works, Who Can Use It, and What to Do With a Mismatch

IRS TIN Matching is the IRS service that tells a payer whether a vendor's name and taxpayer identification number match IRS records before a 1099 is filed. It lets AP catch a bad name or TIN while the vendor is still easy to reach.

The alternative is finding out later. A mismatch that slips through onboarding tends to surface as an IRS notice months after the 1099 went out, when the vendor may have moved on and AP has to send formal letters and possibly start withholding from payments. Running the check up front costs a few seconds per vendor. Nothing here is tax advice, so confirm specifics for your situation with your tax adviser.

Key Takeaways

• IRS TIN Matching checks whether a vendor's name and TIN combination matches IRS records before you file an information return.

• Only payers and their authorized agents who file information returns can use it, and access now requires an IRS account.

• Interactive matching suits checking vendors one at a time at setup, while bulk matching suits a full sweep before 1099 season.

• A mismatch after filing can lead to a CP2100 notice, B notices, and backup withholding, so it's cheaper to catch at onboarding.

• TIN Matching works best as one step in vendor onboarding, alongside a current W-9 and bank-account validation.

What is IRS TIN matching?

IRS TIN Matching is an online program that compares a payee's name and TIN against IRS records and returns a code saying whether they match. Payers use it to validate vendor data before filing Forms 1099 and similar information returns.

The program comes in two forms, according to IRS Publication 2108 (Rev. 11-2024):

• Interactive matching accepts up to 25 name and TIN combinations per session and returns results within 5 seconds.

• Bulk matching accepts a text file of up to 100,000 combinations and returns results within 24 hours. You then have 30 days to retrieve the results file.

Interactive works well for checking new vendors as they're set up. Bulk suits a full sweep of the vendor master before 1099 season.

Is IRS TIN matching free?

Yes. Publication 2108 states that "the IRS does not currently charge a fee" to access the TIN Matching database or to participate in the program. Third-party services that run TIN checks may charge for their own tools, but the IRS program itself carries no fee.

How is TIN matching different from checking a W-9?

A W-9 tells you what the vendor says its name and TIN are. TIN Matching tells you whether the IRS agrees. A W-9 can be complete, signed, and still wrong, because of a typo, an old business name, or a TIN that belongs to someone else.

Collecting the W-9 is the first step. According to the IRS page About Form W-9, the current form is the March 2024 revision, so it's worth checking that new vendors aren't sending older versions. TIN Matching is the second step, confirming that what's on the form matches what the IRS has on file.

Who can use TIN matching, and how do you get access?

Only payers that file information returns, and their authorized agents, can use TIN Matching. The IRS limits access to payers listed in its Payer Account File, and getting in now requires an IRS account.

The IRS Taxpayer Identification Number (TIN) Matching page lays out the requirements. A payer has to be in the Payer Account File, which means it has filed Forms 1099 in the last two years. Users sign in through an IRS account to reach the e-Services application. A company that hasn't filed 1099s recently, such as a new business, won't qualify until it has.

Authorized agents, such as a payroll provider or a tax service, can run matching on a payer's behalf. Whoever runs it, the people with access should be limited and named. TIN Matching shows taxpayer data, so treat access the way you'd treat access to the vendor master itself.

How long does IRS TIN matching take?

Interactive matching returns results within 5 seconds. Bulk matching returns results within 24 hours. The longer wait usually comes before either one, during setup, since the payer has to qualify through the Payer Account File and each user needs an IRS account.

How do you run interactive and bulk TIN matching?

Run interactive matching as part of vendor setup, one vendor at a time, and run bulk matching across the whole vendor master well before year-end. Both use the same codes, so the follow-up process is the same.

For interactive matching during onboarding, the steps usually look like this:

1. Collect a signed, current W-9 from the vendor.

2. Sign in to TIN Matching through your IRS account.

3. Enter the vendor's name and TIN exactly as shown on the W-9.

4. Record the response code and the date in the vendor record.

5. Hold vendor activation until you have a match or a resolved exception.

For a bulk run before 1099 season:

1. Export every active vendor that will receive a 1099, with name, TIN, and TIN type.

2. Format the file as a text file following Publication 2108's layout.

3. Upload it and note the tracking number.

4. Download the results once they're ready, within the retrieval window.

5. Work the non-matching codes before you file.

Timing matters. A bulk run in early fall leaves time to contact vendors. A run in mid-January leaves almost none.

What do the TIN matching response codes mean?

Each TIN Matching result comes back as a single number from 0 to 8. A 0 or a 6, 7, or 8 means the combination matched. The other codes mean something needs fixing before you rely on the data.

Codes from IRS Publication 2108 (Rev. 11-2024).

Code 3 is the one AP sees most in practice, and the cause is often the name rather than the number. A vendor may give its trade name instead of the legal name on file with the IRS, or a sole proprietor may enter a business name instead of their own. Check the name first before assuming the TIN is wrong.

Codes 1 and 4 usually point to your own data entry or file format rather than the vendor, so fix those internally before contacting anyone. Code 2 deserves more care. A TIN the IRS hasn't issued can be a simple typo, but it can also signal a made-up vendor, so check how the vendor was added before asking it for a corrected form.

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What happens when a vendor's TIN doesn't match?

If a mismatch reaches a filed 1099, the IRS may send a CP2100 or CP2100A notice listing the problem accounts. That starts a fixed clock for B notices and possibly backup withholding.

Treat a mismatch as a vendor-master problem first and a tax problem second. The tax steps are what the rules require. The real fix is getting the vendor record right, so the same error doesn't come back next year.

According to IRS Publication 1281 (Rev. 12-2023), the timeline after a CP2100 or CP2100A runs like this:

1. Send the payee a B notice within 15 business days.

2. If no corrected certification arrives, start backup withholding within 30 business days of receiving the notice.

3. Stop withholding within 30 calendar days after receiving a certified W-9 or the required validation.

4. If a second CP2100 names the same payee within three calendar years, send a second B notice, which carries different requirements.

Penalties add to the cost. The IRS page on information return penalties lists per-return amounts for returns due in 2026 of $60 if corrected up to 30 days late, $130 through August 1, and $340 after August 1 or if not filed. Intentional disregard costs $680 per return, with no maximum.

Enforcement has gaps, but that's no defense. According to TIGTA's press release on a 2016 audit of 2013 returns, payers failed to withhold nearly $9 billion in backup withholding on returns with missing or incorrect TINs, and the IRS notified payers on only 57% of those returns. A payer that skips the work is betting on that gap staying open. Holding a payment until a mismatch clears is easier when every payment runs through one flow, as it does when Corpay pays vendors by virtual card, ACH, or check.

What is backup withholding, and when must AP start it?

Backup withholding is federal income tax a payer must withhold from certain payments when a payee's TIN is missing or incorrect. Publication 1281 sets the rate at 24% for subject payments after December 31, 2017.

AP must start backup withholding when a payee doesn't provide a TIN, or within 30 business days of a CP2100 notice if no corrected certification arrives. The threshold for when it applies also changed recently. According to the IRS Instructions for Forms 1099-MISC and 1099-NEC (Rev. December 2026), for tax years beginning after 2025, the reporting and backup withholding threshold for those forms rises to $2,000, and it may be adjusted for inflation starting in 2027. Gross proceeds paid to attorneys stay at $600. Many older guides still quote the old threshold, so update your vendor setup rules.

How do you fix a mismatch with the vendor?

Contact the vendor using details already in your records, explain that the name and TIN don't match IRS records, and ask for a corrected, signed W-9. Then run TIN Matching again on the new information before updating the vendor record.

A few practices make this smoother:

• Ask for the legal name exactly as it appears on IRS records, which may differ from the name on invoices.

• For sole proprietors, confirm whether they're giving an SSN or an EIN and use the matching name.

• Keep the old and new W-9s, the match results, and your contact notes in the vendor file.

• If a vendor won't provide a valid TIN, involve your tax adviser before the next payment.

The guide to 1099-NEC for construction subcontractors covers year-end filing for a vendor group where mismatches are common.

Where does TIN matching fit in vendor onboarding and fraud control?

TIN Matching belongs in vendor onboarding, right after the W-9 and before bank-account validation and the first payment. It confirms the vendor is who it says it is for tax purposes, which also makes it a useful fraud check.

A sound onboarding sequence runs like this:

1. Collect a current W-9 and a signed vendor agreement.

2. Run TIN Matching on the name and TIN.

3. Validate the bank account and confirm ownership with a call to a known contact.

4. Have someone other than the person who entered the vendor approve it.

5. Release the first payment.

The guide to vendor verification and bank validation covers step 3 in detail, and the vendor due diligence checklist covers the rest of what belongs in onboarding.

The fraud case is strong. AFP's 2026 Payments Fraud and Control Survey found 76% of U.S. organizations experienced attempted or actual payments fraud in 2025. The FBI's 2025 Internet Crime Report recorded $3,046,598,558 in reported business email compromise losses across 24,768 complaints. And according to the ACFE's Occupational Fraud 2026 findings, more than half of occupational fraud cases involved a lack of internal controls or an override of existing ones.

A fake vendor set up by an insider often fails TIN Matching, because the name and TIN don't line up with real IRS records. No single check stops every scheme, though this one is hard to fake. Separating who creates vendors from who approves them, as described in the guide to segregation of duties in AP, closes more of the gap. Recording each match result also strengthens your AP audit trail. For more on internal and external schemes, see the overview of accounts payable fraud. Corpay's fully managed AP runs vendor onboarding as part of the service and pays each vendor by virtual card, ACH, or check.

Should you rematch vendors you already pay?

Yes, at least once a year. Vendors change legal names, merge, convert from sole proprietorships to LLCs, and sometimes start using a different TIN. A vendor that matched three years ago may not match today.

A yearly bulk run of every active 1099 vendor, done in early fall, catches most of these changes before they reach a filed return. Pair it with a rule that any change to a vendor's name or TIN triggers a fresh interactive match before the next payment. That rule matters for fraud as much as for tax, because a name change request is one of the ways a fraudster tries to take over a real vendor record.

Who in AP should own TIN matching?

Give TIN Matching to whoever owns the vendor master, usually a vendor-master administrator or a senior AP specialist. The person who runs the match shouldn't also be the person who approves new vendors or releases payments. Keep the list of users with IRS access short, review it when people change roles, and make sure a backup person is trained so the check doesn't stop when someone is on leave.

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Frequently Asked Questions

What is TIN matching?

TIN Matching is an IRS program that checks whether a payee's name and taxpayer identification number match IRS records. Payers use it before filing Forms 1099 to catch errors that could lead to IRS notices, B notices, and backup withholding.

How do I get access to IRS TIN matching?

Your company must file information returns and appear in the IRS Payer Account File, which requires Forms 1099 filed in the last two years. Users sign in through an IRS account to reach the program. Authorized agents can also run matching on a payer's behalf.

How many TINs can I check at once?

Interactive matching accepts up to 25 name and TIN combinations per session. Bulk matching accepts a much larger text file, enough to cover most vendor masters in one run, with results returned within 24 hours.

Is IRS TIN matching free?

Yes. IRS Publication 2108 states that the IRS does not currently charge a fee to access the TIN Matching database or to participate in the program.

What is a B notice?

A B notice is the letter a payer sends a payee after the IRS reports a missing or incorrect name and TIN on a CP2100 or CP2100A notice. It asks the payee for a corrected certification and warns that backup withholding may start.

Did the 1099 threshold change?

Yes. For tax years beginning after 2025, the IRS raised the Form 1099-NEC and 1099-MISC reporting threshold, with possible inflation adjustment from 2027. Attorney gross proceeds kept their old threshold. Check the current IRS instructions each year.

David Luther

Product Marketing Program Manager

David Luther, MBA is a product marketing program manager with years of experience in commercial banking, finance, and technology sectors, with research and writing appearing in financial publications.

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