<Li> Numbers with all zeros in any digit group (000 - ##- ####, ###- 00 - ####, ###- ##- 0000). </Li> <Li> Numbers with 666 or 900 - 999 (Individual Taxpayer Identification Number) in the first digit group . </Li> <P> Until 2011, the SSA published the last group number used for each area number . Since group numbers were allocated in a regular pattern, it was possible to identify an unissued SSN that contained an invalid group number . Now numbers are assigned randomly, and fraudulent SSNs are not easily detectable with publicly available information . Many online services, however, provide SSN validation . </P> <P> Unlike many similar numbers, no check digit is included . </P>

When did social security cards start being issued at birth