TIN Matching Best Practices Before 1099 Filing Season

A name/TIN mismatch found before filing takes a new W-9 to fix. Found after filing, it takes a corrected return, a response to a CP2100 notice, B-notice mailings, possibly backup withholding, and possibly a penalty.

This guide covers how IRS TIN matching works, a fall timeline for running it, what each result code means, and the mistakes that cause corrected records to fail again.

Key takeaways

TIN matching checks whether a payee’s name and TIN combination matches IRS records. It’s free through IRS e-Services for eligible payers.
Run a bulk match of your full vendor file in October, re-match fixes in November and December, and do a final pass in early January.
Codes 0, 6, 7 and 8 are matches. Codes 1, 2 and 3 are the payee data problems that lead to CP2100 notices.
A common mismatch is a sole proprietor’s business name submitted with their SSN. Match against the legal name on Line 1 of the W-9.
Keep dated records of every match and every W-9 request. That file is your reasonable cause defense if a penalty notice ever arrives.

What IRS TIN matching is (and isn’t)

The IRS TIN Matching program lets payers check a payee’s name and TIN against IRS records before filing an information return. It answers one question: will this name/TIN pair match when the IRS processes your 1099?

It does not tell you the correct name for a TIN or the correct TIN for a name; the IRS won’t disclose either. It also doesn’t confirm that the person who signed the W-9 is the person the TIN belongs to.

Who can use it. TIN matching is limited to payers, and their authorized agents, who file information returns reporting income subject to backup withholding. That covers most 1099-NEC, 1099-MISC, 1099-INT, 1099-DIV, 1099-B and 1099-K filers. The payer must appear in the IRS Payer Account File, which generally means it filed those forms within the last two years. Applying and using the service requires an IRS account.

W-2 employers use a different tool: the Social Security Administration’s Social Security Number Verification Service (SSNVS).

Two ways to match. Limits and turnaround times below are from the IRS TIN matching tools page.

Two ways to match.

Option	Volume	Results	Best for
Interactive	Up to 25 name/TIN pairs per request, 999 requests per 24 hours	Immediate	Vendor onboarding and one-off W-9s
Bulk	Up to 100,000 pairs per .txt file	Within 24 hours, via the IRS secure mailbox	Year-end sweeps of the full vendor file

Both options are free and return the same result codes. Bulk files must follow the IRS file format, including a TIN type code for each record (1 = EIN, 2 = SSN, 3 = unknown).

A fall TIN matching timeline

When	What to do
Early October	Pull every payee paid in 2026 (or expected to be). Run a bulk match of the full file.
Mid-October to November	Work the exceptions by result code. Send W-9 requests to payees with codes 1, 2 or 3.
November to December	Re-match every corrected record the day the new W-9 arrives. Follow up on non-responders. For payees added this year with no TIN on file, send the first annual solicitation by December 31.
Early January	Match payees added since October, plus any name or TIN changes made in your AP system.
Before you transmit	Confirm no unresolved mismatches remain, or document your solicitation attempts for each one.

Starting in early October gives payees about four months to respond before the February 1, 2027 deadline. Starting in January gives them a few weeks, during the busiest weeks of their own year.

TIN matching best practices

Build a clean extract first. Send only payees you’ve paid or will pay this year. Remove duplicates, strip hyphens and spaces from TINs, and check that spreadsheet exports haven’t dropped leading zeros. Include the correct TIN type code wherever you know it.
Match the legal name, not the business name. Use the name on Line 1 of the W-9. A sole proprietor’s DBA goes on Line 2. If you submit “Green Leaf Landscaping” with John Smith’s SSN, it will fail. For a single-member LLC that’s disregarded for tax purposes, the W-9 instructions put the owner’s name on Line 1 and the LLC’s name on Line 2, so match the owner’s name with the owner’s SSN or EIN.
Match every payee, not just those over the threshold. Payment totals change between October and December, and the 1099-NEC and 1099-MISC threshold rose to $2,000 for 2026 payments, which shifts who’s reportable. See our 2026 threshold guide. Matching everyone avoids a last-minute scramble.
Re-verify recurring vendors every year. Businesses restructure, merge and get new EINs. Individuals change names after marriage or divorce. Last year’s match isn’t this year’s guarantee.
Re-match every fix before you close it. A new W-9 is a new claim, not a verified one. Run it through interactive matching the day it arrives.
Add interactive matching to vendor onboarding. The fall sweep catches the backlog; checking each new W-9 before the first payment stops the backlog from forming. A mismatch result on its own doesn’t require backup withholding; that obligation comes from a missing TIN or an IRS notice. Matching early lets you fix the record before either happens.
Use the program the way it’s meant to be used. Match only payees you actually pay. Submitting the same TIN under different names triggers a 96-hour lockout of your TIN Matching access.
Document everything. Keep the dated results file for each match, copies of W-9 requests, and payee responses. If you ever receive a Notice 972CG proposed penalty, this record is the core of a reasonable cause response.

How to read TIN matching result codes

Every record comes back with a code from 0 to 8. Codes 0, 6, 7 and 8 are matches. Codes 1, 2 and 3 are payee data problems. Codes 4 and 5 are problems with your request, not the payee.

Code	Meaning	What to do
0	Name/TIN combination matches	No action. Save the result.
1	TIN missing or not 9 digits	Check your file for stripped zeros or bad formatting. If the TIN really is missing, request a W-9. Backup withholding applies to payments made while you have no TIN.
2	TIN not currently issued	Request a new W-9. Treat it as a fraud flag until resolved.
3	TIN is issued, but not with this name	Check for DBA vs. legal name issues first, then request a corrected W-9.
4	Invalid request	Fix the record format (letters or special characters in the TIN) and resubmit.
5	Duplicate request	Remove duplicates from your file.
6	Matched on SSN (TIN type sent as unknown)	Match. Record the payee as an individual in your vendor master.
7	Matched on EIN (TIN type sent as unknown)	Match. Record the payee as an entity.
8	Matched on both SSN and EIN	Match. Confirm which TIN type the payee used on the W-9.

Codes 6 through 8 are worth acting on even though they pass. They appear only when you submit the TIN type as unknown, and they tell you the TIN type in your vendor master may be wrong, which is useful to fix before you build filing files.

Working a code 3. Code 3 results are often real vendors with a paperwork problem, not bad actors. Before requesting a new W-9, check whether you keyed the business name for a sole proprietor, misspelled the name, or used a former name. If your records look right, send the payee a blank Form W-9 and explain which name the IRS expects.

What an unmatched TIN costs after you file

A mismatch that reaches the IRS starts a chain: a CP2100 or CP2100A notice (issued in October and April), B-notices mailed within 15 business days, 24% backup withholding if payees don’t respond, and possibly a Notice 972CG proposed penalty. For more, see our second B-notice guide.

For returns due in 2027, the per-return penalty for an incorrect information return is $60 if corrected within 30 days of the due date, $130 if corrected by August 1, and $340 after that. Annual caps reach $4,191,500 for larger businesses (Rev. Proc. 2025-32). Intentional disregard carries a higher per-return penalty with no cap. See our guide to 1099 correction penalties for how the tiers apply.

Does IRIS make TIN matching unnecessary?

No. IRIS checks recipient name/TIN combinations when you submit, but a mismatch doesn’t stop the filing. The record comes back “Accepted with Errors,” counts as filed, and has to be fixed with a corrected return. By then you’re in filing week and the payee statements may already be mailed. Pre-filing matching remains the only point where fixing a record costs nothing. More on the switch in our FIRE to IRIS transition guide.

Talk to Tab Service about pre-filing TIN verification or call 312-527-4306.