Java Regex to Validate SSN (Social Security Numbers)

In this java regex tutorial, we will learn to use regular expressions to test whether a user has entered a valid Social Security number in your application or website form.

Valid SSN Number Format

United States Social Security numbers are nine-digit numbers in the format AAA-GG-SSSS with following rules.

  • The first three digits called the area number. The area number cannot be 000, 666, or between 900 and 999.
  • Digits four and five are called the group number and range from 01 to 99.
  • The last four digits are serial numbers from 0001 to 9999.

To validate all above 3 rules, our regex would be:

Regex : ^(?!000|666)[0-8][0-9]{2}-(?!00)[0-9]{2}-(?!0000)[0-9]{4}$

Explanation of Regex of Validate SSN

^            # Assert position at the beginning of the string.
(?!000|666)  # Assert that neither "000" nor "666" can be matched here.
[0-8]        # Match a digit between 0 and 8.
[0-9]{2}     # Match a digit, exactly two times.
-            # Match a literal "-".
(?!00)       # Assert that "00" cannot be matched here.
[0-9]{2}     # Match a digit, exactly two times.
-            # Match a literal "-".
(?!0000)     # Assert that "0000" cannot be matched here.
[0-9]{4}     # Match a digit, exactly four times.
$            # Assert position at the end of the string.

Now let’s test our SSN validation regex using some demo SSN numbers.

List<String> ssns = new ArrayList<String>();
      
//Valid SSNs
ssns.add("123-45-6789");  
ssns.add("856-45-6789");  

//Invalid SSNs
ssns.add("000-45-6789");  
ssns.add("666-45-6789");  
ssns.add("901-45-6789");  
ssns.add("85-345-6789"); 
ssns.add("856-453-6789"); 
ssns.add("856-45-67891"); 
ssns.add("856-456789"); 

String regex = "^(?!000|666)[0-8][0-9]{2}-(?!00)[0-9]{2}-(?!0000)[0-9]{4}$";

Pattern pattern = Pattern.compile(regex);

for (String number : ssns)
{
	Matcher matcher = pattern.matcher(number);
	System.out.println(matcher.matches());
}

Output:

true
true

false
false
false
false
false
false
false

I will advise to play with above simple regular expression to try more variation.

Happy Learning !!

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