SSN Validation Are there any guides to validating social security numbers?

John Zukowski

The first three digits of an SSN map to the location where the number was requested. The Social Security Administration maintains a list of valid digit mappings at http://www.ssa.gov/foia/stateweb.html.

With a few holes, 001-772 are valid. So, if a number begins with 000 or something greater then 773, you know it is invalid. 729-749 are currently not allocated. Many others are allocated but not used yet.

Other than that, the only real rule is length (11 digits) and where the dashes go (position 4 and 7).