An ignition interlock device can allow some California drivers to maintain driving privileges following a DUI arrest or conviction. In other cases, installation is mandatory.
Whether an IID is required—and how long it must remain installed—depends on several factors, including the number of prior DUI convictions, whether anyone was injured, whether alcohol was involved, and whether the restriction arises from a DMV action or criminal conviction.
California extended its statewide ignition-interlock pilot program through December 31, 2032. Anyone facing a DUI should therefore understand how an IID works, when it may be required, and what must be done to remain compliant.
What Is an Ignition Interlock Device?
An ignition interlock device, commonly called an IID, is a breath-testing instrument connected to a vehicle’s ignition system.
Before the vehicle will start, the driver must provide a breath sample. If the device detects alcohol above its programmed limit, the engine will not start.
The device may also request additional breath samples after the vehicle has started. These are commonly known as rolling retests. A failed or missed retest does not ordinarily shut off a moving vehicle, which could create a safety hazard. Instead, the device records the event and may activate an alarm until the driver provides a passing sample or turns off the vehicle.
The IID records information that may include:
- Attempts to start the vehicle
- Breath-test results
- Missed or failed retests
- Disconnection attempts
- Suspected tampering
- Maintenance and calibration history
California requires IIDs to be installed and serviced by authorized providers.
Is an IID Required After Every California DUI?
No. An IID is not automatically mandatory in every California DUI case.
The requirement depends on whether the person is:
- A first-time or repeat DUI offender
- Accused or convicted of an alcohol-related or drug-only DUI
- Involved in an injury-producing incident
- Seeking an IID-restricted license after a DMV suspension
- Subject to a discretionary court order
- Eligible for an exemption
California’s statewide program generally requires an IID for repeat alcohol-related DUI convictions and DUI convictions involving injury. A court may also order an IID in a first-offense case.
A first-time, noninjury, alcohol-related offender may have options that include voluntarily obtaining an IID-restricted license or, in qualifying cases, applying for a restriction permitting driving for employment and an approved DUI program.
California’s Mandatory IID Periods
Under current California DMV guidance, mandatory IID periods for alcohol-related convictions generally depend on the person’s prior DUI history.
DUI without injury
The general mandatory periods are:
- No prior DUI convictions within 10 years: No automatic mandatory IID period under the statewide program, although the court may order installation for up to six months.
- One prior DUI conviction within 10 years: One year.
- Two prior DUI convictions within 10 years: Two years.
- Three or more prior DUI convictions within 10 years: Three years.
- One or more prior felony DUI convictions: Three years.
DUI involving injury or vehicular manslaughter
The general mandatory periods are:
- No prior DUI convictions within 10 years: One year.
- One prior DUI conviction within 10 years: Two years.
- Two or three prior DUI convictions within 10 years: Three years.
- One or more prior felony DUI convictions: Four years.
These periods address the statewide IID program. A court order, DMV administrative action, license status, or another conviction may affect the actual restriction.
The California DMV statewide IID program provides the current requirements and mandatory-period table.
Options for a First-Time DUI
A first-time DUI without injury is treated differently from a repeat or injury-related offense.
Following a first alcohol-related DUI conviction, a judge may order an IID for up to six months. When no IID has been ordered, a qualifying driver may generally choose between:
- An IID-restricted license for up to six months, allowing driving in a properly equipped vehicle; or
- A one-year restricted license permitting travel to, from, and during employment and to and from the required DUI program.
The appropriate choice depends on the driver’s job, family obligations, access to vehicles, financial circumstances, and ability to satisfy the DMV requirements.
A driver should not assume that installing an IID alone immediately restores driving privileges. The DMV must approve and issue the restricted license.
An IID After a DMV Administrative Suspension
A DUI arrest can produce a DMV Administrative Per Se proceeding that is separate from the criminal court case.
For a first non-refusal APS suspension, a qualifying driver may be able to obtain an immediate IID restriction for up to four months. A repeat non-refusal offender may be eligible for an IID restriction for up to one year.
Time completed under an APS-related IID restriction may count toward a later mandatory IID period if the person is convicted. The interaction between the two cases should be confirmed with the DMV because eligibility depends on the specific driving record and disposition.
A driver generally has only 10 days after receiving the suspension or revocation order to request a DMV hearing. Obtaining an IID restriction does not replace the need to address that deadline.
Requirements for an IID-Restricted License
Before the DMV will issue an IID-restricted license, the driver generally must:
- Resolve other outstanding suspensions or revocations.
- Have an IID installed by an authorized provider.
- Submit a Verification of Installation, generally using DMV form DL 920.
- Enroll in or complete the applicable DUI education program.
- Provide an SR-22 or other required proof of financial responsibility.
- Pay the applicable restriction, reissue, and administrative fees.
Additional requirements may apply depending on the offense, prior record, refusal allegation, or court order.
The driver must wait until the DMV confirms that the restricted driving privilege is effective before driving.
Must an IID Be Installed in Every Vehicle?
An IID restriction generally prohibits a person from operating a vehicle that does not have a functioning, certified device.
The precise installation requirements can depend on vehicle ownership and the applicable court or DMV order. Complications may arise when someone:
- Owns multiple vehicles
- Shares a vehicle with family members
- Does not own a vehicle
- Drives an employer-owned vehicle
- Uses a company vehicle connected to a business the person owns
- Has access to a motorcycle
A person who does not own or have access to a vehicle may be eligible to request an exemption. An exemption can carry significant consequences, including serving the full suspension or revocation period instead of driving with an IID.
Employer-Owned Vehicles
California provides a limited employer-vehicle exception for some drivers with IID-restricted licenses.
A person may be permitted to operate an employer-owned vehicle during the course and scope of employment without an IID if the requirements are satisfied. The driver generally must notify the employer of the restriction and complete the required DMV notice.
The driver should retain proof of that notice as required. The exception generally does not apply when the restricted driver owns or controls the business that owns the vehicle.
The employer exception should be confirmed before operating the vehicle. Driving first and attempting to correct the paperwork later can lead to serious consequences.
How Often Must an IID Be Serviced?
An installed IID must be calibrated and inspected by a certified installer at intervals not exceeding 60 days.
Missing appointments can be reported to the DMV or court. The provider may also report:
- Removal of the device
- Attempts to bypass or tamper with it
- Repeated failures to comply with calibration or maintenance requirements
- Other violations recorded by the equipment
Drivers should keep copies of installation records, service receipts, calibration reports, DMV submissions, and removal authorization.
Can Another Person Provide the Breath Sample?
No. Asking someone else to provide a sample so the restricted driver can operate the vehicle is unlawful.
California also prohibits another person from knowingly providing a sample to enable a restricted driver to use the vehicle.
Attempts to bypass, remove, or tamper with the IID may be recorded and reported. The resulting consequences can include:
- Extension of the IID period
- Loss of restricted driving privileges
- Probation-violation proceedings
- Additional criminal allegations
- Delay in full license reinstatement
What Causes Failed IID Tests?
An IID is designed to detect alcohol in a breath sample. Alcohol may come from an alcoholic beverage, but certain products can temporarily introduce alcohol into the mouth.
Possible sources include:
- Alcohol-containing mouthwash
- Breath sprays
- Some medications
- Certain food products
- Recent use of hand sanitizer in an enclosed vehicle
- Residual alcohol from a recent drink
A failed test does not necessarily establish that the driver was impaired. The device records the result, however, and repeated failures may create complications.
Drivers should follow the provider’s instructions, avoid alcohol-containing products before testing, wait the required time after eating or drinking, rinse with water when appropriate, and complete any permitted retest.
A person disputing recorded violations should preserve the device logs, receipts, medical information, video, and other evidence that may explain the result.
How Much Does an IID Cost?
Costs vary among authorized providers and may include:
- Installation
- Monthly equipment rental
- Calibration and monitoring
- Removal
- Lockout or reset services
- Missed-appointment charges
- Administrative and DMV fees
Qualified low-income participants may be responsible for only a portion of certain mandatory IID costs. Eligibility and the required application should be discussed with an authorized provider or the DMV.
Drivers should request a complete written fee schedule before choosing a provider. The lowest advertised installation charge may not represent the lowest total cost over the full restriction period.
The DMV maintains a current list of approved IID manufacturers and devices.
Can an IID Be Removed Early?
A driver should not remove an IID merely because the anticipated period has passed.
Removal should occur only after confirming that:
- The required period has been completed;
- The court has not imposed a longer term;
- The DMV has authorized removal;
- All program and financial-responsibility requirements have been satisfied; and
- No violation or compliance issue has extended the restriction.
Unauthorized early removal may be reported and could delay restoration of unrestricted driving privileges.
The IID Program Was Extended in 2026
California’s statewide IID pilot program was originally scheduled to expire at the end of 2025. Assembly Bill 366 extended the program through December 31, 2032.
Accordingly, the statewide program continues to govern qualifying DUI offenses in 2026. The California DMV confirmed that the extension took effect January 1, 2026. Read the DMV’s 2026 IID extension notice.
Contact McGinity Law Office
An IID may provide a way to continue driving, but installation is only one part of complying with a DUI-related license restriction. The driver must also satisfy the court order, DMV requirements, DUI-program obligations, insurance requirements, and applicable deadlines.
Mistakes involving installation, employer vehicles, service appointments, exemptions, or early removal can extend the process or create new legal problems.
Contact McGinity Law Office to discuss whether an IID is mandatory, available as an optional restriction, or appropriate under the circumstances of a California DUI case.
Brian D. McGinity
California State Bar No. 212891
McGinity Law Office
Phone: 530-513-6836
Website: www.bmcglaw.com
This article provides general information about California law and does not constitute legal advice. Reading it or contacting McGinity Law Office does not, by itself, establish an attorney-client relationship. IID and licensing requirements depend on the individual’s record, offense date, court orders, and DMV status. Past results do not guarantee a similar outcome.