TIN Matching is a service offered by the IRS to help payers verify the Taxpayer Identification Number (TIN) and name combination of their payees against IRS records. Verifying this data up front helps you avoid CP2100/2100A "B-notice" letters, backup-withholding requirements, and penalties for incorrect information.
What Is TIN Matching?
The IRS TIN Matching program lets payers confirm — before filing — that a payee's TIN (SSN, ITIN, or EIN) and legal name agree with IRS records. It's especially valuable for filers of 1099, ACA, and W-2 forms.
Step-by-Step Process
- Submit a request. After enrolling in IRS e-Services, an authorized payer (or its designated agent) can send up to 25 name/TIN pairs for an immediate on-screen response, or up to 100,000 pairs in a single bulk-file upload through the IRS TIN Matching application.
- IRS validation. Each pair is compared with the IRS master file. The system returns a single-character response code ("0" through "5") indicating an exact match, partial match, or no match.
- Review & correct. Any code other than "0 — Exact Match" signals a discrepancy. Investigate spelling errors, transposed digits, or name changes and obtain corrected information from the payee before issuing forms.
- Eligibility. You may use the TIN Matching system if you filed at least one information return in either of the two preceding tax years.
Why TIN Matching Matters
A TIN error on a Form 1099 means the name/TIN pair you reported doesn't match the IRS master file. Mismatches stem from typos, nicknames, recent name changes, or obsolete EINs/SSNs. If the problem isn't fixed promptly, you risk backup-withholding requirements and escalating information-return penalties.
Proactive TIN Matching before filing virtually eliminates B-Notices and backup-withholding headaches by confirming the name/TIN pair in real time. Always obtain a fresh Form W-9 from new payees and keep records of all validation attempts.
What Happens if a TIN Doesn't Match IRS Records?
If a TIN doesn't match IRS records, the IRS will likely notify the payer through a CP2100 or CP2100A notice. This notification serves as a prompt for the payer to take corrective action.
The payer is required to begin backup withholding on any reportable payments to the payee if the TIN continues to mismatch even after issuing a "B Notice" to the payee. The "B Notice" instructs the payee to correct any information and provide a properly completed Form W-9 to the payer.
If the payer does not comply with the backup withholding requirement, they may become liable for paying the uncollected amount and potentially incur penalties.
Is TIN Matching Required to File With the IRS?
While TIN matching is not technically required to file with the IRS, it is highly recommended. It is a proactive measure that helps payers verify name/TIN combinations before submitting forms and avoid backup-withholding notices and potential penalties.
It's particularly beneficial for those who make reportable payments subject to backup withholding and for high-volume filers. The IRS does not mandate its use; it is an optional tool available to assist filers in reducing errors.
Bulk TIN Verification with BoomTax
Manually checking TINs through the IRS portal is fine for a handful of payees, but at scale you need automation. TINCorrect (powered by BoomTax) handles bulk verification:
- Upload your payee list via CSV or spreadsheet.
- Run validation against the IRS master file for thousands of records at once.
- Review mismatches with clear, actionable error reports.
- Re-verify after corrections as many times as needed before filing.
Catch errors before they become penalties — let BoomTax handle TIN validation as part of every 1099, 1095, and W-2 filing workflow.
