SSN Validator
Check a US Social Security Number format.
What makes an SSN structurally invalid?
- Area number (first 3 digits) of 000, 666, or 900–999.
- Group number (middle 2 digits) of 00.
- Serial number (last 4 digits) of 0000.
- Well-known invalid numbers like 078-05-1120 (the 1938 wallet-card SSN) and 219-09-9999.
This free SSN validator checks whether a US Social Security Number isstructurally valid according to the Social Security Administration's format rules. It confirms the nine-digit shape and rejects numbers with an invalid area, group or serial block, plus known-invalid numbers that were never issued. It does not and cannot tell you whether a number was actually assigned to a real person — no such lookup is publicly available, and this tool is intended for form validation and test data only.
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