Social Security The Official Website of the U.S. Social Security Administration
Updated 12/04/2012 12:01 PM | ID# 425
Determining Social Security numbers
Which Social Security numbers are invalid?
An invalid Social Security number is one that we never assigned.
On June 25, 2011, we began assigning Social Security numbers differently than in the past. Today, Social Security numbers are assigned through a randomized process.
However, there are some 9 digit numbers that we do not include in our randomized process. We do not assign a Social Security number with the first three digits of:
· 000
· 666
· 900 - 999
Nor do we assign Social Security number with "00" in the fourth and fifth position, or "0000" in the last four positions of the numbers.
Additionally, prior to June 25, 2011, we had never assigned a Social Security number with the first three digits of:
· 000
· 666
· 772 - 799
· 800 - 899
· 900 - 999
Employers can use the Social Security Number Verification Service to verify the names and Social Security numbers of former and current employees.