Ever wonder if your passport number actually signifies anything, like where you live or your age? The answer is simple: no. In the United States, passport numbers are not assigned based on any particular markers.

Passport application locator numbers, however, are a different story. These nine digits are assigned to you when you apply for or renew a passport, and can be used for checking the status of your application. The first two numbers indicate the processing facility for your passport. (You can see the full list of processing locations and their corresponding two-digit numbers on the U.S. Department of State Bureau of Consular Affairs website.) But your application locator number will not be your passport number.

American passport numbers were previously nine digits, but since the State Department began issuing the Next Generation Passport in 2021, passport numbers are alphanumeric codes that begin with a single letter and end with a string of eight digits.

It’s also worth noting every individual passport book has a unique number. So, if you’re renewing your passport, your new book will have a different number from your old one.

There’s another important identifying number that might have some key indicators into you individually: your social security number. If you were born before June 25, 2011, your social security number was tailored specifically to a geographic location, either of the social security office that issued your number or of the mailing address used on your application. But since June 25, 2011, social security numbers have been randomized.

Driver’s license numbers may also have identifiers, depending on the state (as each state numbers its licenses differently). Some examples include converting your name or initials into numbers and including a numerical code that indicates your birth month and date.