Vehicle Code 23140 makes it unlawful for a driver under 21 to drive with a blood-alcohol concentration of 0.05% or more.
It is an infraction — no jail — but it triggers a one-year license suspension, which is what makes it worth fighting.
What VC 23140 Says
VC 23140 applies to drivers under 21 with a BAC of 0.05% or more — a lower threshold than the 0.08% standard, reflecting California’s stricter rules for underage drivers. It is charged as an infraction.
How It Differs From a DUI
A driver under 21 at 0.08% or above can still be charged with a standard DUI (VC 23152) — a misdemeanor. VC 23140 is the lower-level infraction for the 0.05%–0.08% range, and California’s separate zero-tolerance law reaches any measurable alcohol (0.01%+) with a civil license penalty.
Consequences and Defenses
As an infraction, VC 23140 carries a fine and, critically, a one-year driver’s-license suspension — the consequence that matters most to a young driver. Defenses focus on the accuracy of the test and the lawfulness of the stop. The DMV process and the court case can both affect the license.
Frequently Asked Questions
Is an underage DUI a misdemeanor or an infraction?
VC 23140 — a driver under 21 with a BAC of 0.05% or more — is an infraction, carrying a fine and a one-year license suspension but no jail. A driver under 21 at 0.08% or above can instead be charged with a standard misdemeanor DUI under VC 23152.
What is the penalty for an underage DUI in California?
VC 23140 is an infraction, so there is no jail. The main consequences are a fine and a one-year driver's-license suspension — which is usually the reason to fight the charge.
What is the BAC limit for drivers under 21?
California is strict for underage drivers: VC 23140 applies at 0.05% or more, a standard DUI (VC 23152) can apply at 0.08% or above, and the zero-tolerance law reaches any measurable alcohol (0.01% or more) with a civil license penalty.
GuidesComplete Guide to California Misdemeanors · Glossary · Penalties Reference.
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Ahmed S. Hasan
San Francisco Criminal Defense Attorney · State Bar of California #364992
Ahmed S. Hasan is the founder of ASH Legal, a solo criminal defense practice based in San Francisco. The firm runs on flat-fee representation: one lawyer, one fee, from arraignment through resolution. No hourly billing. No surprise invoices.
Ahmed is a graduate of Emory University School of Law and a member in good standing of the State Bar of California (Bar #364992). His practice focuses on San Francisco misdemeanor defense — DUI, domestic violence, petty theft and shoplifting, drug possession, vandalism, trespassing, and assault and battery — with particular attention to diversion-track outcomes that end in dismissal under PC 1001.95, PC 1001.36 (Mental Health Diversion), PC 1001.80 (Military Diversion), and PC 1001.83 (Parental Caregiver Diversion).
Ahmed previously served as a post-bar clerk with the San Francisco Public Defender's Office, the city's largest indigent-defense practice. He is a member of the Asian Pacific American Bar Association of Silicon Valley.
He represents clients at the San Francisco Hall of Justice (850 Bryant Street) and the Civic Center Courthouse. The ASH Legal office is at 15 Boardman Place, Suite 301, San Francisco, CA 94103.
Free 30-minute consultations are available by phone or Zoom. (510) 545-6515 · ahmed@ashlegal.com