Driver's license numbers follow a formula unique to each state

Your driver's license number is not random. Each state uses its own system to generate the number printed on your license, and most states encode information about you into those digits. Some states use your name, date of birth, or sex. Others use a sequence based on when you applied. A few states switched systems partway through, so two people born the same year might have completely different number formats.

The number serves as your identifier in the state's licensing database. When a police officer runs your license, that number pulls up your record. When you renew, you typically keep the same number for life — even if you move to a different state, your original state's number stays on your license.

Understanding how your state assigns these numbers won't change anything about your license, but it explains why your number looks the way it does and why you cannot choose or change it yourself.

Key Takeaways

  • Most states encode your name, birth date, or sex into your driver's license number using a mathematical formula specific to that state.
  • A few states use sequential numbering based on the order you applied, which reveals nothing about you from the number alone.
  • Your state's system determines your number when you first get a license; you cannot request a different one.
  • If you move to a new state, your original license number stays the same — you do not get renumbered.
  • Some states changed their numbering system over time, so older and newer licenses may use different formats.

States that encode your name into the number

Several states use a soundex algorithm or similar name-coding system to turn your surname into digits. The formula typically takes the first letter of your last name plus a mathematical conversion of the remaining letters. New York, for example, has historically used a system where the first digit represents your sex and birth century, and the next digits encode your last name and birth date.

This approach means two people with the same last name and birth date will have similar license numbers. It also means someone looking at your number could theoretically reverse-engineer part of your identity, though most people never do. States that use this method have not changed it because millions of licenses already exist under that system, and switching would require reissuing every license in the state.

States that use birth date and sex

Other states, including some that have modernized their systems, embed your date of birth and sex directly into the number. The format might be MMDDYY (month, day, year) followed by a sequence number to distinguish people born on the same day. Some states add a digit for sex — typically an odd number for male, even for female, though this varies.

This system is straightforward to generate and straightforward for staff to verify: they can glance at your number and confirm it matches your stated birth date. However, it also means your birth date is visible in your license number to anyone who knows the state's format, which is why some privacy advocates have pushed states to move away from this method.

States that use sequential numbering

A smaller number of states assign driver's license numbers sequentially based on when you applied, with no personal information encoded. These numbers reveal nothing about you from the digits alone. The state straightforward issues the next number in line when you walk in to get your license.

This approach is more privacy-protective but requires the state to maintain a database to track which numbers have been issued. It also means the state cannot quickly verify your birth date or sex by looking at your number — they have to look it up in the system. States that use this method tend to be those that modernized their licensing systems more recently.

What happens when a state changes its numbering system

Some states have switched from one system to another over the past 20 years. When this happens, people who got their license before the switch keep their old-format number. People who get a license after the switch receive a number in the new format. This is why you might see two valid driver's licenses from the same state with completely different number structures.

A state might make this change for privacy reasons, to reduce fraud, or to accommodate a larger population. When the switch happens, the state does not reissue existing licenses just to change the number. You keep your original number unless you renew for other reasons — such as expiration or a name change — and even then, some states let you keep your old number if you request it.

How to find out your state's system

Your state's Department of Motor Vehicles (DMV) or equivalent agency can tell you how your license number was assigned. You can contact them by phone or through their website. Some states publish this information publicly because it is not sensitive — the formula itself is not a secret, only the process of it to your specific data.

If you are curious whether your number encodes your birth date, you can try comparing your license number to your actual birth date and see if you spot a pattern. If your state uses a soundex system, the pattern will be less obvious. If you cannot figure it out from your own license, the DMV can explain it directly.

Why you cannot change your driver's license number

Your driver's license number is assigned by the state's system and is tied to your record in their database. You cannot request a different number, and the state will not issue you a new one just because you dislike the current one. The number is permanent for the life of your license in that state.

If you move to a different state and get a new license there, you will receive a new number in that state's format. Your old state's number remains on your old license, but it is no longer active. Some states allow you to keep your old license as an ID even after you move, though it cannot be used for driving.

Frequently Asked Questions

Can someone figure out my birth date from my driver's license number?

It depends on your state's system. If your state encodes birth date directly into the number, then yes — anyone who knows the format can extract it. If your state uses a soundex name code or sequential numbering, no. You can contact your DMV to learn which system your state uses.

Why do some people's license numbers start with different digits?

This usually means they were issued under a different system or at a different time. Some states changed their numbering formula, or different counties within a state may have used different prefixes. It can also reflect the order in which licenses were issued if your state uses sequential numbering.

If I move to a new state, do I get a new license number?

Yes. Your new state will issue you a new license number in its own format. Your old state's number is no longer active, though it remains on your old license if you keep it. The two numbers are separate and do not connect to each other in any system.

What if there is an error in my license number?

Contact your state's DMV when ready. If the number was generated incorrectly due to a data entry error — for example, your birth date was entered wrong — the DMV can correct it. You may need to renew your license or request a replacement, depending on your state's policy.

Are driver's license numbers used for anything besides driving?

Yes. Your license number is used as an ID for many purposes: opening a bank account, renting an apartment, boarding a plane, or verifying your identity. This is why the number is printed on the front of your license. It serves as a state-issued identifier, not just a driving credential.