Washington Driver License Numbers Decoded

Washington State encodes your last name, first initial, middle initial, and your date of birth into your driver’s license number. This online program by Alan De Smet will calculate them for you.

His site also has the best explanation I could find of how the system works:

These license numbers look like the following:

• WOO**JT547KA - “John T. Woo” born on May 1st, 1946
• WALKECR577DU - “Christopher R. Walken” born on March 31st, 1943
• LLLLLFMYYXmb - Pattern deciphered below

Deciphering the Number

LLLLL - Last Name, truncated - The first five characters are the first five letters of the last name. If the name is shorter than five characters, the extra space is padded with asterisks (*).

F - First Initial

M - Middle Initial - If no middle initial the space is padded with an asterisk (*).

YY - Year of birth, encoded - This is 100 minus the the two digit year of birth. So someone born in 1998 will be 2 (100-98), as will someone born in 1898.

X - Checksum - This can be calculated if you like math.

m - Month of birth, encoded. Look up your birth month on this table. There are two options. In general the state will use the first column. If another person has generated the same license number as you, they’ll use the second column. This is most often needed for twins. (I have no idea what they do after that.)

d - Day of month of birth, encoded - Look up the code for your birth’s day of month.