Register for the IRS e-Services TIN Matching program at the IRS website; approval is required before you can access the service and is limited to payers subject to backup withholding reporting (Form 1099).
Once approved, log into the IRS e-Services portal and use either the interactive (single) TIN matching tool for one-off checks or upload a bulk file for batch matching of multiple payees.
For bulk matching, prepare a pipe-delimited or comma-delimited text file with each row containing the TIN type (SSN or EIN), the TIN number, and the name as it appears on the payee's tax return.
Submit the bulk file and wait for the IRS to process it (results are typically returned within 24 hours); download the results file from the e-Services portal.
Parse the result codes: code '0' means the TIN and name combination matches IRS records; other codes indicate mismatches, invalid TINs, or that the name/TIN combination is not on file.
For payees with non-matching results, follow IRS backup withholding procedures (currently 24% withholding) and request a W-9 correction before disbursing payments.
Known gotchas
IRS TIN Matching is only available to authorized payers and is not a general-purpose identity verification API; it cannot be used for KYC purposes outside the backup withholding context.
The IRS TIN Matching program is a portal-based service, not a REST API; there is no programmatic API for direct integration—you must use the e-Services portal or work through an authorized third-party intermediary.
TIN matching results confirm name/TIN combinations against IRS records as of a point in time; they do not confirm that a person is who they claim to be or that the payee is not sanctioned.
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