Free Tool
TIN Format Validator
Paste a list of TINs - one per line - and instantly see which ones have format problems before you submit to IRS TIN matching. Catches the issues that cause IRS result codes 1 and 4: hyphens, 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. SSNs (###-##-####) and EINs (##-#######) with or without hyphens are both accepted - hyphens are stripped automatically before validation. Leading and trailing spaces are trimmed.
TIN type hint:
Error Breakdown
A TIN can have multiple issues simultaneously (e.g., hyphens and wrong length after stripping). 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
Hyphens present
Auto-fixable
123-45-6789 or 12-3456789 - IRS bulk file requires 9 raw digits, no hyphens or spaces.
Wrong length
Needs fix
Fewer than 9 digits (common when Excel strips leading zeros) or more than 9 (paste artifacts).
Leading zeros stripped
Excel issue
012345678 becomes 12345678 when opened in Excel without text formatting - results in an 8-digit TIN that fails IRS validation.
Non-numeric characters
Needs fix
Letters, slashes, or other characters embedded in the TIN - typically a data entry or copy-paste issue.
All-same digit (000…, 999…)
Invalid
000000000, 999999999, 111111111 etc. - structurally valid format but known IRS-rejected placeholder values.
SSN pattern anomalies
Suspect
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).
EIN prefix out of range
Suspect
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.
Empty / blank line
Skipped
Blank entries in your list - skipped in validation count but flagged so you know they exist.
Ready to run IRS TIN matching on your cleaned list?
TIN Comply runs bulk IRS TIN matching - no IRS e-services enrollment required. Upload your fixed TIN list and get official IRS match/mismatch results in hours. We also handle W-9 outreach for any mismatches, CP2100 remediation, and sanctions screening - all in one platform.