SSN validator

Check whether a US Social Security number is structurally valid per the SSA rules. Format only — never enter a real person's SSN.

Format AAA-GG-SSSS Check SSA rules

Input

SSN check

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Enter a US Social Security number to check it against the SSA format rules.

A Social Security number is structurally valid when the area is not 000, 666, or 900–999, the group is not 00, and the serial is not 0000. This checks structure only — it cannot confirm a number was ever issued, and you should never enter a real person's SSN.

Awaiting input

A free SSN validator that checks a US Social Security number against the SSA's structural rules — nine digits in AAA-GG-SSSS format, with reserved area numbers (000, 666, 900-999), group 00, and serial 0000 excluded. Format check only — do not enter a real person's SSN into any online tool.

How to check an SSN format

Enter the SSN in hyphenated (123-45-6789) or plain (123456789) format.
The validator normalizes the input and checks the total length is exactly 9 digits.
It verifies the area number is not 000, 666, or in the 900-999 range.
It confirms the group number is not 00 and the serial is not 0000.

SSA structural rules applied

The Social Security Administration assigns nine-digit numbers under rules that exclude certain combinations: area number 000 has never been issued; area number 666 was reserved and never issued; area numbers 900-999 are reserved for non-SSN uses such as Individual Taxpayer Identification Numbers (ITINs). Within valid area numbers, group 00 and serial 0000 are also excluded. Since the SSA moved to randomized assignment in 2011, any number not matching these exclusions could theoretically be a valid SSN — structural checks can only confirm what cannot be valid, not what is.

Privacy notice

Never enter a real SSN into any online tool unless you fully trust and control it.
This validator runs entirely in your browser — nothing is transmitted.
Use it only with fictional or generated test numbers.
Real SSN validation (e.g., identity verification) requires SSA E-Verify or equivalent authorized service.

Frequently asked questions

Does a valid SSN format mean the number was issued by the SSA?

No. Structural validation only confirms the number does not fall in a known-invalid range. Since 2011 randomization, nearly any 9-digit number outside the excluded ranges could theoretically be issued — format cannot confirm issuance.

Is it safe to enter an SSN into this validator?

The tool runs locally in your browser and transmits nothing. That said, we recommend only entering fictional or test numbers — never enter a real person's SSN into any website as a habit.

Why are area numbers 000 and 666 invalid?

Area 000 has never been issued by the SSA. Area 666 was similarly withheld. Area numbers 900-999 are reserved for ITINs and other non-SSN identifiers used by the IRS.

What is the difference between an SSN and an ITIN?

An SSN is issued by the SSA to US citizens and authorized residents. An ITIN (Individual Taxpayer Identification Number) is issued by the IRS to individuals who need a tax ID but are not eligible for an SSN — they begin with 9 and use area numbers in the 900-999 range.