California “Implied Consent” Law – How It Works

California’s implied consent law is simple: If you get lawfully arrested for DUI, then you are presumed to have consented to take a breath test or blood test to measure your BAC.

Vehicle Code 23612 states that:

A person who drives a motor vehicle is deemed to have given his or her consent to chemical testing of his or her blood or breath for the purpose of determining the alcoholic content of his or her blood, if lawfully arrested for an offense allegedly committed in violation of Section 23140, 23152, or 23153. If a blood or breath test, or both, are unavailable, then paragraph (2) of subdivision (d) applies.

California’s implied consent law only applies to breath and blood tests after an arrest. This means that you can still refuse to take a preliminary alcohol screening (PAS) breath test before being arrested.

The consequences for refusing a test following an arrest include:

1. Enhanced penalties in addition to the standard DUI penalties, and
2. A mandatory driver’s license suspension even if your charge is dropped.¹

Our California DUI attorneys will highlight six key things to know about implied consent in California:

• 1. PAS Breath Tests
• 2. Refusing Breath Tests
• 3. Refusing Blood Tests
• 4. Mandatory Blood Tests
• 5. Defenses to Refusing
• 6. Out-of-state Drivers
• Additional Reading

1. PAS Breath Tests

After you are pulled over for impaired driving in California, you may be asked to take a hand-held preliminary alcohol screening (PAS) breath test.²

This is basically a roadside breath test and is just another field sobriety test (FST) – like walking in a straight line. An FST simply helps police decide whether or not to arrest you for driving under the influence.

Since you have not been arrested by this point, there is no penalty for refusing to take a PAS breath test unless you are either:

• under the age of 21, or
• on probation for a prior DUI conviction.³

Further, your refusal to take a PAS test may not be admitted at trial as evidence of guilt (as long as you are at least 21 and not on DUI probation).⁴

Note that if you agree to a PAS test, the test results can be used at trial to help convict you of drunk driving.⁵

2. Refusing Breath Tests

In California, there are basically two potential consequences for violating the implied consent law by refusing a breath test. These are:

1. you will lose your driver’s license for some period of time after refusing the test, and
2. you will face enhanced penalties in addition to the standard California DUI penalties.

The enhanced penalties for a breath test refusal are outlined in this chart:

DUI Refusal	Additional Punishment in California
First offense	An additional 48 hours in county jail and a minimum nine-month California DUI school (in lieu of the three-month program for first-time DUIs that do not involve refusals)
Second offense within 10 years	an additional 96 hours in county jail
Third offense within 10 years	an additional 10 days in county jail
Fourth of subsequent offense within 10 years	an additional 18 days in county jail

3. Refusing Blood Tests

California’s implied consent law used to apply to both breath and blood tests in California. Then in 2016, the U.S. Supreme Court case Birchfield v. North Dakota said it is unconstitutional for a state to make it a crime to refuse a blood test without a lawful warrant.

The Birchfield case dealt with states that make it a separate crime to refuse a blood test after an arrest. California, in contrast, just imposes additional penalties for refusing blood tests.

So, it remains for courts to decide if California’s “implied consent” law is also unconstitutional with regard to blood tests.

4. Mandatory Blood Tests

There are three conditions in which California police can require you to take a blood test following a DUI arrest. These are when there is:

1. a warrant for the test,
2. suspicion of a felony DUI, and/or
3. suspicion of DUID (drugged driving).

Warrant for a Chemical Test

Police officers can require you to submit to a blood test when they have a valid warrant for it.

A warrant is issued by a judge and provides the legal authorization for, in this context, a chemical test.

Suspicion of a California Felony DUI

California police officers may use a forcible draw of your blood for a chemical test when

• they suspect a felony DUI, and
• a warrant cannot be quickly obtained.

Driving under the influence becomes a felony when:

• it causes injury⁶,
• you have three or more DUI or wet reckless convictions within the prior 10 years⁷, or
• you have had at least one prior felony DUI conviction.⁸

Suspicion of a DUID

An officer can require you to submit to a blood test if they have a clear indication that it would show the presence of drugs.

An officer may gain a “clear indication” via:

• your statements,
• objective symptoms of drug intoxication, and/or
• physical evidence of drug use.

5. Defenses to Refusing

There is one common defense that we can raise if you are charged with a DUI test refusal. This is to show that your arrest was not “lawful.”

An example is if the arresting officer did not have reasonable suspicion for a traffic stop or probable cause for a DUI arrest.

If your arrest was not lawful, then you never gave implied consent to a breath test. This defense can work to dismiss your entire criminal case.

6. Out-of-state Drivers

The implied consent law applies to all motorists in California. This includes both:

• California residents that have a California State license, and
• Non-California residents holding an out-of-state license.

Additional Reading

For more in-depth information, refer to these scholarly articles:

• The Privacy Implications of DUI Refusals and Forced Blood Alcohol Tests: What Judges Can Do – Criminal Justice.
• Keeping DUI Implied Consent Laws Implied – Willamette Law Review article about the utility of chemical test refusal laws.
• Admissibility of Refusal to Submit to Blood Alcohol Test – Nova Law Journal article about whether chemical test refusals can be used as evidence in a trial.
• Refusal to Submit to a Chemical Test: Whether Refusing Really Counts as a Refusal – JFK University Law Review.
• The Admissibility of Refusals in Drunk Driving Prosecutions: A Violation of the Fifth Amendment – Pacific Law Journal.

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