The document number on your driver’s license is almost always printed on the back of the card, labeled DD, and it’s a separate string from your driver’s license number. It identifies the specific piece of plastic in your wallet rather than your driving record, so it changes every time a new card is issued to you.
Look for the DD Label
Flip your license over and scan for the letters “DD” followed by a run of numbers, or a mix of letters and numbers. Under the national card design standard published by the American Association of Motor Vehicle Administrators, this field carries the abbreviation “DD” and the on-card reference “4d,” and the number has to uniquely identify your particular card from any others issued to you in the past.1American Association of Motor Vehicle Administrators. 2020 AAMVA DL/ID Card Design Standard Most states print it on the back near the top. A few put it on the front, near the expiration date or the photo.
Not every state uses the “DD” label. You might see any of the following instead:
- Doc #
- Document Number
- Audit Number
- Inventory Control Number
- Control Number
They all point to the same field. If you see a long alphanumeric string on the card that doesn’t match the number printed on the front, that’s almost certainly it.
How It’s Different From Your License Number
The license number identifies you. It stays with you across renewals and replacements and ties to your driving record. The document number identifies the card. Every time your state issues you a new physical card, whether for a renewal, a replacement after a loss, or an address change, the document number changes while the license number stays put.
The two numbers also tend to look different. License number formats vary a lot by state: some are 7-digit numeric codes, some use an alphabetic prefix with 12 or more digits, and some use longer alphanumeric patterns. The document number typically runs 8 to 14 alphanumeric characters depending on the issuing state.2E-Verify. Tips for Entering Driver’s Licenses and ID Cards in E-Verify A difference in length or character pattern between a number on the front and a number on the back is usually the easiest visual cue that you’re looking at two separate fields.
When You’ll Be Asked for It
Most people don’t think about the document number until a form demands it. The common thread across these requests is that something is trying to verify you hold a current card, not just that you know a license number from memory.
- Employment verification. More than 80 percent of employees present a driver’s license as proof of identity for Form I-9. States participating in E-Verify’s RIDE program require employers to enter the document number, not just the license number, to validate the card against state DMV records.3E-Verify. Driver’s License Verification
- Online voter registration. Several states ask for both the driver’s license number and the document number when you register to vote online. The document number confirms you have the physical card in front of you.
- State DMV online accounts. Setting up or logging into your state’s DMV portal often requires the document number from your most recently issued card as a security step.
- Government benefit applications. Some federal and state agencies request the document number during online identity verification to confirm the credential is current and hasn’t been superseded by a replacement.
Because the number ties to a specific card rather than to your identity in the abstract, it’s the field that tells a verification system whether what you’re holding is the current one.
If You Can’t Find It
Start with your state’s DMV website. Most agencies publish diagrams showing where every field appears on current and recent card designs. Card layouts change over time, so a license issued five or ten years ago may have the number in a different spot than one issued last year.
If the number is worn off, printed in micro-text you can’t read, or simply isn’t where the diagram says it should be, contact your state’s DMV. Very old licenses issued before AAMVA standardized the document discriminator field may not have a clearly marked document number at all. In that case, requesting a replacement is the simplest fix. A newly issued card carries a current document number in the standard location, and replacement fees in most states run somewhere between $10 and $30.
One thing to watch for after any new card arrives: the document number on your old card becomes invalid. Any form, account, or registration tied to the old number will need the updated one. People regularly renew their license and then wonder why their DMV online account or voter registration portal rejects the document number they’d been using for years. Update stored document numbers whenever you receive a new card.
A Note on Protecting It
The document number by itself is less sensitive than your full license number, date of birth, or Social Security number. The real risk is that a photo of your license hands over every field at once, document number included, which can help someone pass identity checks that rely on document-level validation.
A few habits help. Don’t text or email photos of your license unless you have to, and crop or redact fields the recipient doesn’t need. Be aware that businesses scanning your license for age verification pull every barcode field, document number included. Check your credit reports periodically and set up bank transaction alerts. If your license is lost or stolen, request a replacement promptly: the new card gets a new document number, which effectively invalidates the old one for any verification system checking against current DMV records.