DMV & Licenses
Ignition Interlock Devices (IID) in California DUI Cases
California requires ignition interlock devices for most DUI convictions. An IID allows you to drive during a license suspension — but comes with strict compliance requirements. Learn what to expect and how an attorney can minimize your IID obligation.
By Michael P. Kade — Former LAPD Officer & Criminal Defense Attorney · Updated
Educational purposes only — not legal advice. This article provides general information about California DUI law and does not create an attorney-client relationship. Consult a licensed attorney for advice specific to your situation.
Key Takeaways
- —California requires IID installation for most DUI convictions under SB 1046
- —An IID allows you to drive during a license suspension — without it, you cannot drive at all
- —IID requirements range from 6 months (first offense) to 4 years (fourth offense)
- —Monthly IID rental and monitoring costs typically run $70–$100 per month
- —Tampering with or circumventing an IID is a separate criminal offense
An ignition interlock device is a breath testing instrument installed in your vehicle that requires you to provide a breath sample before the engine will start. If the device detects alcohol above a set threshold (typically 0.02%), the vehicle will not start. California law requires IID installation for most DUI convictions, and the device must remain installed for a period ranging from 6 months to 4 years depending on the offense.
IID Requirements Under California Law
Under California Vehicle Code § 23700 (SB 1046, effective January 1, 2019), the DMV requires IID installation for all DUI convictions in California. For a first offense, the IID must be installed for 6 months. For a second offense within 10 years, the IID period is 1 year. For a third offense within 10 years, the IID period is 2 years. For a fourth or subsequent offense within 10 years, the IID period is 3 years. If the DUI involved injury, the IID period is extended: 1 year for a first offense with injury, 2 years for a second, and 3 years for a third.
How the IID Works
The IID is installed by a state-approved vendor and connects to your vehicle's ignition system. Before starting the vehicle, you must blow into the device. If your breath alcohol concentration is below the set threshold, the vehicle starts normally. The device also requires periodic 'rolling retests' while driving — you must provide a breath sample within a set time window while the vehicle is in motion. If you fail a rolling retest, the device logs the failure and triggers an alarm (horn and lights) until you pull over and turn off the engine.
Costs and Compliance
IID installation typically costs $70–$150, and monthly rental and monitoring fees run $60–$100. California offers a fee waiver or reduction program for low-income drivers. You must have the device calibrated and the data downloaded at regular intervals (typically every 60 days) by the vendor. All data — including failed tests, tampering attempts, and missed calibration appointments — is reported to the DMV and the court. Violations can result in an extension of the IID period or revocation of your restricted license.
Driving Without an IID
Under Vehicle Code § 23247, driving a vehicle not equipped with a required IID, or circumventing the device, is a separate criminal offense punishable by up to 6 months in county jail and a fine of up to $5,000. The DMV will also extend the IID requirement period. If you need to drive a vehicle that does not belong to you — such as an employer's vehicle — you must notify your employer of the IID requirement, and the employer must certify that they are aware of the requirement.
Penalties at a Glance
| Offense / Situation | Potential Penalty |
|---|---|
| First DUI conviction | IID required for 6 months |
| Second DUI within 10 years | IID required for 1 year |
| Third DUI within 10 years | IID required for 2 years |
| Fourth+ DUI within 10 years | IID required for 3 years |
| Driving without required IID | Up to 6 months jail; up to $5,000 fine; extended IID period |
Penalties shown are general ranges. Actual sentences depend on the specific facts of your case.
How Attorney Kade Defends These Cases
- —Negotiate a plea that minimizes the IID period or avoids IID entirely (e.g., wet reckless)
- —Challenge the underlying DUI conviction to avoid the IID requirement altogether
- —Apply for the low-income IID fee waiver to reduce the financial burden
- —Advise the client on employer vehicle exemption procedures
- —Challenge IID violation reports that are the result of equipment malfunction
- —Seek early termination of the IID period upon showing of compliance
- —Advise on the consequences of IID violations before they escalate
Frequently Asked Questions
While you are not legally required to have an attorney, a DUI conviction carries serious consequences — fines, license suspension, possible jail time, and a permanent criminal record. An experienced DUI attorney can challenge the evidence, negotiate with prosecutors, fight your DMV hearing, and potentially get charges reduced or dismissed. The cost of an attorney is almost always less than the long-term cost of a DUI conviction.
A California DUI case typically takes 3 to 12 months to resolve, depending on the county, the complexity of the case, and whether it goes to trial. Misdemeanor DUI cases in Los Angeles County often take 4 to 8 months. Felony DUI cases take longer. Your attorney can give you a more specific estimate based on the facts of your case and the court's current caseload.
After a DUI arrest: (1) Do not make any statements to police beyond identifying yourself. (2) Contact a DUI attorney as soon as possible — ideally within 24 hours. (3) Call the DMV Driver Safety Office within 10 days to request an APS hearing or your license will be automatically suspended. (4) Write down everything you remember about the stop, the tests, and the arrest while it is fresh.