I agree and I understand that (I work in the financial and insurance industry). I didn't mean to imply that SSNs are unique, but that they should be and if they are not, then as soon as someone learns that their SSN is not unique, it needs to be reported (for the individual's own future). Still, SSNs or ITINs are required more now than they were before for security purposes and less often for non-essential reasons. In the past they were used for poor reasons (id cards being one of them - I have BCBS and my old id card membership number uses my SSN and that changes January 1st, 2006). Mostly to track money in the U.S. to prevent (not possible but it is their goal) and track terrorist funding. That really is what Sarbane-Oxley is all about - not SEC regulations.


>Tracy, most healthcare and insurance providers are moving away from SSN completely. I know that Blue Cross of CA completely reissued insurance cards mid-year last year to remove SSN in favor of their own ID. In deference to HIPAA, the healthcare industry is taking great pains to remove use of SSN.
>
>And uniqueness is NOT guaranteed. (Yes, it drives the IRS and SSA nuts.) They've never made any bones about non-uniqueness, particularly dating from a time when the numbers were assigned regionally instead of centrally.
>
>
>>I agree that an SSN should not be used as a PK, but it should be unique.