Using partial SSN as employee ID: Is that legal?

Q. Can we use the last four digits of our employees’ Social Security number (SSN) as their employee identification number? It would make tracking hours on our log-in time clock much easier. — J.G., Oklahoma

A. In most circumstances, the answer would be that you could indeed use the last four digits as an identifier. However, you should check whether any laws or regulations in your state prohibit the use of partial SSNs in situations like these.

In the past few years, many states have passed laws aimed at reducing identity theft by restricting the use of SSNs and requiring employers to safeguard the numbers.