IRS TIN Matching Bulk File Format: How to Prepare, Submit, and Interpret Results

What Is IRS Bulk TIN Matching?

The IRS TIN Matching Program is a pre-filing service that lets authorized payers verify name/TIN combinations against IRS records before submitting information returns. Validating before filing is the mechanism the IRS itself recommends for reducing CP2100 notices and information return penalties.

Two modes are available:

• Interactive TIN Matching — up to 25 name/TIN combinations per session, results returned immediately. Best for spot-checking individual vendors.
• Bulk TIN Matching — up to 100,000 name/TIN combinations per file, results returned within 24 hours via secure mailbox. Required for any meaningful pre-filing validation of a vendor population.

Both programs are accessed through IRS e-Services at irs.gov/e-services.

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Before You Can Submit: Registration and Eligibility Requirements

The IRS TIN Matching Program is not open to everyone. Before submitting a bulk file, you must:

1. Be listed on the IRS Payer Account File (PAF). The PAF is populated when you file at least one information return. If your organization has never filed a 1099 or other information return with the IRS, you won't be in the PAF and can't access TIN Matching directly. File at least one return first.

2. Register for IRS e-Services. This requires completing the online identity verification process. The Principal — the individual registering on behalf of the organization — must verify their identity and complete the application. Once registered, the Principal can assign access to other users within the organization.

3. Complete a TIN Matching Application. Even after e-Services registration, you must separately apply for access to the TIN Matching program. Access is not automatic.

4. Only submit name/TIN combinations for payees for whom a reportable payment is made or likely to be made. The IRS program exists for payers validating their own reporting population — it cannot be used to verify TIN data unrelated to your information return obligations. Confidentiality requirements apply: results may only be used for tax reporting purposes and must not be disclosed.

For most organizations with an established 1099 filing history, steps 1–3 are one-time setup. The eligibility restriction in step 4 is the ongoing operational constraint.

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The Bulk File Format

Each record in the bulk file is a single line in a plain text (.txt) file. Fields are separated by semicolons. The format for each record:

TIN_TYPE;TIN;NAME;ACCOUNT_NUMBER

• TIN_TYPE — required. Use 1 for EIN, 2 for SSN, 3 for unknown.
• TIN — required. Must be exactly 9 digits, numeric only. No hyphens, spaces, or formatting.
• NAME — required. Up to 40 characters. Strict character restrictions apply (see below).
• ACCOUNT_NUMBER — optional. Up to 20 alphanumeric characters, for your internal tracking. The IRS returns this field unmodified in results; it is not validated.

Example records:

1;123456789;ABC Corporation;VEND-0042
2;987654321;Jane Smith;
3;112233445;Smith & Co;

The file has no header row. Records begin on line 1.

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Name Field Rules: Where Most Files Break

The name field is where bulk files most commonly fail. The IRS applies strict character restrictions and specific name control logic when matching.

Allowed characters in the name field:

• Letters (A–Z, a–z)
• Numbers (0–9)
• Spaces
• Hyphens ( - )
• Ampersands ( & )

Not allowed:

• Apostrophes ( ' ) — remove them. "O'Brien" becomes "OBrien"
• Commas ( , ) — remove them. "Smith, John" becomes "Smith John"
• Periods ( . ) — remove them. "J. Smith" becomes "J Smith"
• Any other special characters or punctuation

Name control logic — the IRS doesn't match against the full name string. It extracts a name control (typically the first four significant characters of the last name for individuals, or the first four characters of the business name for entities) and matches on that. This means:

• For individuals, use last name first: Smith John, not John Smith. The IRS SSN database uses last-name-first format.
• For sole proprietors who provided a business name on their W-9, use the individual's legal name, not the DBA. The TIN is tied to the person, not the trade name.
• For single-member LLCs disregarded for tax purposes, use the owner's name and SSN/EIN, not the LLC name.
• For business entities, use the exact legal name as it appears on their EIN registration — not a DBA, not an abbreviation, not a shortened form.

The 40-character limit applies to the full name string. Long legal names must be truncated at 40 characters. When truncating, preserve the beginning of the name — the IRS name control is derived from the first characters.

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TIN Field Rules

• 9 digits exactly — no hyphens, no spaces, no formatting. 12-3456789 and 123 456 789 will both fail. The field must contain 123456789.
• All numeric — no letters or special characters.
• Leading zeros matter — a TIN that begins with 0 must be formatted with the leading zero. 012345678 is a valid 9-digit TIN; 12345678 (8 digits) is not.
• Avoid common data export formatting errors — Excel will strip leading zeros from numeric fields unless the column is formatted as text. This is one of the most common causes of bulk file failures when exporting from spreadsheets or ERPs.

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TIN Type Field: When to Use "Unknown"

If you know a vendor is a business entity, use TIN type 1 (EIN). If you know a vendor is an individual, use TIN type 2 (SSN). If you're uncertain — for example, a sole proprietor who may have provided either their SSN or an EIN — use TIN type 3 (unknown).

When TIN type is 3, the IRS checks both the SSN and EIN databases:

• Result code 6 — matched on SSN
• Result code 7 — matched on EIN
• Result code 8 — matched on both (the TIN/name combination appears in both databases)
• Result code 3 — no match in either database

Using 3 for everything is not a workaround for not knowing entity types. It adds processing overhead and produces less diagnostic information. Use it for genuinely ambiguous cases only.

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Result Codes: What Each One Means

The IRS returns your file with the same fields plus a result code appended to each record:

Code	Meaning	Action
0	Match — TIN/name combination matches IRS records	No action needed
1	TIN missing or not a 9-digit number	Fix the TIN format; re-validate
2	TIN not currently issued	TIN doesn't exist in IRS records; request new W-9
3	TIN/name combination does not match IRS records	Name or TIN is wrong; investigate and request corrected W-9
4	Invalid request (formatting error)	Fix the file format for that record; re-submit
5	Duplicate request	Already submitted this combination; result is suppressed
6	Matched on SSN (TIN type was unknown)	Match confirmed via SSN database
7	Matched on EIN (TIN type was unknown)	Match confirmed via EIN database
8	Matched on both SSN and EIN (TIN type was unknown)	Match confirmed in both databases

Code 3 vs. Code 2: Code 2 means the TIN itself doesn't exist — it was never issued. Code 3 means the TIN exists but is associated with a different name. These require different follow-up: Code 2 typically means a data entry error or a fabricated number; Code 3 usually means a name mismatch that a corrected W-9 can resolve.

Code 5 — duplicate handling: The IRS will not return results for a TIN/name combination already submitted by the same payer within the same session or recently. Re-submitting the same combination to circumvent this generates a security lockout: if the IRS system detects the same EIN researching the same TIN under different names, it blocks account access for 96 hours. This is an anti-abuse mechanism, not a bug.

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Submission and Results Timeline

Step	Details
File format	Plain text (.txt), no header row, semicolon-delimited
Maximum records per file	100,000 name/TIN combinations
Processing time	Results available within 24 hours
Results location	IRS secure mailbox (accessible via e-Services)
Mailbox retention	30 days from when results are available
Retention after opening	3 days — download promptly after accessing
System availability	24 hours/day except Sunday 12 a.m.–4 p.m. ET

If you open your results file and need a copy later, retrieve it within 3 days. After that it's purged. Download and store results locally as part of your compliance documentation.

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Preparing Your Vendor File: A Practical Checklist

Before submitting a bulk file, run through these checks:

• File saved as plain .txt, not .csv or .xlsx
• No header row
• Semicolons as delimiters (not commas, tabs, or pipes)
• All TINs are exactly 9 digits, numeric only, no hyphens
• Leading zeros preserved (format TIN column as text before exporting from Excel)
• Names truncated to 40 characters maximum
• Apostrophes, commas, and periods removed from name field
• Individual names formatted last name first
• Sole proprietors using legal name, not DBA
• Single-member LLC records using owner name and owner TIN
• No duplicate TIN/name combinations in the file
• TIN type set correctly (1, 2, or 3)

The most common cause of mass Code 4 results is a delimiter error — exporting from Excel as CSV and leaving commas as field separators instead of converting to semicolons.

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IRS Bulk vs. TIN Comply Bulk: Key Differences

The IRS program is free and authoritative, but it has structural constraints that matter at scale:

Feature	IRS Direct	TIN Comply
Max records per file	100,000	No artificial limit
Results turnaround	Up to 24 hours	Typically within the hour
File format required	Strict IRS .txt format	Upload Excel, CSV, or TXT — auto-formatted
Additional validations	TIN matching only	TIN matching + EIN lookup + sanctions screening in one file
Duplicate handling	Code 5 / potential lockout	Automatic duplicate detection and recombination
Extra data columns	Not supported	Unlimited — passed through untouched
API access	Not available	Full API for upload and result retrieval
Registration requirement	IRS e-Services + PAF listing	No IRS registration required
Audit trail	Manual	Dashboard with full validation history

For organizations filing 1099s with a large vendor population, TIN Comply's bulk processing handles the real-world complexity that IRS direct submission doesn't accommodate — files exported from ERPs with extra columns, vendor lists over 100,000 records, and the need to run TIN matching, EIN lookup, and sanctions screening from a single submission.

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Frequently Asked Questions

Can I use IRS TIN Matching for W-2 employees? No. The IRS TIN Matching Program is for payers of 1099-reportable income subject to backup withholding. W-2 employee SSN verification is handled separately through the Social Security Administration's SSN Verification Service (SSNVS).

What if a vendor gets a Code 3 but insists their TIN is correct? Code 3 means the TIN and name don't match IRS records together — it doesn't always mean the TIN is wrong. The mismatch may be a name formatting issue (DBA vs. legal name, sole proprietor vs. LLC, truncation) rather than a wrong TIN. Request a new W-9 and ask the vendor to confirm the exact legal name as it appears on their tax return or EIN assignment letter.

Does a Code 0 guarantee I won't get a CP2100? Not entirely. TIN matching validates the name/TIN combination as of the date you run it. If a vendor's information changes between your pre-filing validation and the IRS processing your 1099 (for example, a name change after marriage or a business name change), a mismatch could still appear. The IRS explicitly acknowledges this scenario in its FAQ for the program. Running TIN matching close to filing season reduces the gap.

Can I submit the same vendor list twice? No. The IRS program restricts re-submission of previously submitted TIN/name combinations. Submitting a full vendor list, reviewing results, correcting mismatches, and then re-submitting only the corrected records is the intended workflow — not re-submitting the full list.

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This article is for informational purposes only and does not constitute legal or tax advice. Consult a qualified professional for guidance specific to your organization.