Free Tool

TIN Format Validator

Paste a list of TINs - one per line - and instantly see which ones have format problems, for the IRS TIN Matching bulk file and IRIS A2A XML (no dashes) or the IRIS portal CSV (dashes required). Catches the issues that cause IRS result codes 1 and 4: wrong length, leading zeros stripped by Excel, non-numeric characters, and SSN/EIN pattern mismatches.

Processed entirely in your browser - nothing is uploaded

One TIN per line, or whole rows pasted from a spreadsheet (tab, comma, pipe or semicolon separated). The tool finds the TIN column, keeps a header row if there is one, and carries the other columns (name, account, anything else) through the results, the copy and the export. SSNs (###-##-####) and EINs (##-#######) with or without dashes are both accepted; the target you pick decides whether dashes are required or must be removed.

Checking for:

TIN Matching bulk file and IRIS A2A XML: 9 digits, no dashes or spaces. Dashes are flagged and stripped for you.

Coming from IRIS? The two IRIS formats differ: the portal CSV wants dashed TINs, the A2A XML wants 9 bare digits like the TIN Matching bulk file. Pick the matching target above, or check the whole file with the IRIS 1099 File Checker.

TIN type hint:

Error Breakdown

A TIN can have multiple issues simultaneously (e.g., dashes and wrong length). Each issue is counted separately. The table below shows all issues per TIN.

Full Results

#	Original Input	Cleaned TIN	Length	Detected Type	Status	Issues Found	Suggested Action

TINs are displayed as entered. This tool processes everything locally in your browser - no data is transmitted to any server.

IRS Submission Readiness

What This Validator Checks

Dashes

The IRS TIN Matching bulk file and the IRIS A2A XML require 9 raw digits, no dashes or spaces. The IRIS portal CSV requires the opposite: 123-45-6789 for an SSN or ITIN, 12-3456789 for an EIN. The tool checks whichever target you picked.

Auto-fixable

Wrong length

Fewer than 9 digits (common when Excel strips leading zeros) or more than 9 (paste artifacts).

Needs fix

Leading zeros stripped

012345678 becomes 12345678 when opened in Excel without text formatting - results in an 8-digit TIN that fails IRS validation.

Excel issue

Non-numeric characters

Letters, slashes, or other characters embedded in the TIN - typically a data entry or copy-paste issue.

Needs fix

All-same digit (000…, 999…)

000000000, 999999999, 111111111 etc. - structurally valid format but known IRS-rejected placeholder values.

Invalid

SSN pattern anomalies

SSN area number 000, or group number 00, or serial 0000 - structurally invalid per SSN issuance rules. Also flags the notorious 078-05-1120 (Woolworth test SSN).

Suspect

EIN prefix out of range

EINs starting with 00, 07–09, 17, 18, 19, 28, 29, 49, 69, 70, 78, 79, 89, or 96–99 are not valid IRS-issued EIN prefixes.

Suspect

Empty / blank line

Blank entries in your list - skipped in validation count but flagged so you know they exist.

Skipped

Ready to run IRS TIN matching on your cleaned list?

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Questions people ask

What does a TIN format check actually catch?

It catches the mistakes the IRS rejects on sight: a TIN with the wrong number of digits, an SSN whose area number cannot exist (000, 666 or 900 to 999 outside the ITIN range), an EIN with a prefix the IRS never issued, hyphens or spaces in a bulk file, and leading zeros that a spreadsheet dropped. It does not tell you whether the TIN belongs to the name; only IRS TIN Matching does that.

Do I enter TINs with or without dashes?

It depends where they are going, which is why the tool asks. The IRS TIN Matching bulk file and the IRIS A2A XML both want 9 bare digits with no dashes or spaces. The IRIS Taxpayer Portal CSV templates want the opposite: SSNs and ITINs as XXX-XX-XXXX and EINs as XX-XXXXXXX, and the portal rejects an undashed TIN. Pick the target above the input and the tool flags and fixes the TINs for that format. To check a whole IRIS file, use the IRIS 1099 File Checker.

Is an ITIN formatted like an SSN?

Yes, nine digits in the same 3-2-4 pattern, but an ITIN always starts with 9 and has a fourth and fifth digit in the ranges the IRS assigns to ITINs (50 to 65, 70 to 88, 90 to 92 and 94 to 99). A number that starts with 9 outside those ranges is not a valid ITIN or SSN.

Can a valid-looking TIN still fail IRS TIN Matching?

Often. Format is only the first gate. The IRS matches the TIN against the name on its records, so a correctly formatted SSN paired with a business name, or a maiden name, or a DBA, comes back as a mismatch and later as a CP2100 notice. Run IRS TIN Matching on every new payee before the first payment.

Is anything I type sent to a server?

No. The checks run in your browser with JavaScript. Nothing is uploaded, logged or stored; you can run the page with the network disconnected.