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When You Must Identify

Penal Code 148.9 — no general duty to name yourself, and no false name

In California, the Penal Code section on identifying oneself to an officer punishes a false identity, not silence. Falsely representing oneself as another person or a fictitious person to a peace officer upon a lawful detention or arrest, to evade the process of the court or proper identification, is a misdemeanor.

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The situationWhat the code asks for
The situationDriving a motor vehicle on a highwayWhat the code asks forPresenting the driver's license for examination on a peace officer's demand
The situationArrested for an infractionWhat the code asks forOnly a driver's license or other satisfactory evidence of identity, and a signature on the promise to appear
The situationArrested for an infraction with no identificationWhat the code asks forThe officer may ask for a thumbprint on the notice to appear
The situationAny lawful detention or arrestWhat the code asks forNo false or fictitious name or identity

On an infraction, custody is the exception. A person arrested for an infraction may be taken into custody only if the person refuses to sign a written promise to appear, has no satisfactory identification, or refuses to provide a thumbprint or fingerprint.

Willfully resisting, delaying or obstructing a peace officer in the discharge of a duty is a separate offense, punishable by a fine of up to $1,000, up to one year in county jail, or both.

A driver arrested for a Vehicle Code violation who does not present a license or other satisfactory evidence of identity, with an unobstructed view of the full face, is taken before a magistrate rather than released on a notice to appear.

Sources for this section (5)
  1. Penal Code 148.9 — False identification to a peace officer
  2. Penal Code 853.5 — Release on a citation for an infraction, and satisfactory identification
  3. Veh. Code 12951 — Possession and display of a driver's license
  4. Penal Code 148 — Resisting, delaying, or obstructing an officer
  5. Veh. Code 40302 — When a person arrested for a Vehicle Code violation is taken before a magistrate

Legal information, not legal advice. Verified as of September 2026. Applying it to a particular situation is the work of a licensed California attorney.

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