Michigan is one of eleven states which create the Driver's License (DL) number using an algorithm called the Soundex Code. Using this algorithm, a person's first name, full middle name (or middle initial), last name, birth day and birth month (but not year) are combined to create a unique number starting with the first initial of his or her last name.
 
Other states using the Soundex Code are Florida, Illinois, Maryland, Minnesota, Nevada (prior to Jan 1998), New Hampshire, New Jersey, New York (prior to Sep 1992) Washington and Wisconsin.
 
If you received an error message saying that the DL is invalid, but the format is OK (e.g., in Michigan it starts with the first letter of the person's last name and is followed by four groups of three numbers), the invalid number may mean:
  • You entered the person's middle initial, but the driver's license has the full middle name
  • You entered the person's full middle name but the driver's license has the middle initial
  • The birth month or birth day was entered incorrectly
  • The DL is fraudulent

One other possibility can occur: the Soundex Code can generate the same results for more than one person born on the same day of the year. If that occurs, the state changes the last group of numbers to make the DL unique. Often those exceptions to the algorithm do not get distributed as quickly as they should. If the member has a new DL, this might be the reason.