Ignition Interlock Devices (IID) in Washington

An ignition interlock device (IID) is a breath alcohol monitoring system installed in a vehicle after certain DUI or alcohol-related offenses. It is designed to prevent a vehicle from starting if alcohol is detected in the driver's breath.

In Washington, ignition interlock requirements are governed by RCW 46.04.215 and related statutes.

How an Ignition Interlock Device Works

An IID requires the driver to provide a breath sample before the engine will start. If the device detects alcohol at or above the programmed threshold (generally 0.025 BAC), the vehicle will not start.

While driving, the device will also require periodic “rolling retests” to ensure continued compliance.

Modern devices typically include:

  • Camera verification
  • Data logging
  • Calibration and monitoring requirements
  • Reporting to the Department of Licensing

Ignition Interlock License (IIL)

If your license is suspended following a DUI arrest or conviction, you may apply for an Ignition Interlock License (IIL). This allows restricted driving privileges provided that:

  • An IID is installed in all vehicles you operate; and
  • You maintain compliance with all monitoring requirements.

The IIL allows driving for work, school, medical appointments, and other lawful purposes.

How Long Is an IID Required?

The required IID period depends on prior offenses and the nature of the conviction. Typical minimum periods include:

  • First DUI offense: 1 year
  • Second DUI offense: 5 years
  • Third or subsequent DUI offense: 10 years

Additional requirements may apply if there are prior alcohol-related convictions.

Compliance Requirements

Before full license reinstatement, drivers must demonstrate compliance during the final monitoring period. Reinstatement may be delayed if the driver:

  • Attempts to start the vehicle with a BAC of 0.04 or higher;
  • Misses required retests;
  • Fails to complete required maintenance, calibration, or monitoring appointments.

Costs of an IID

Drivers are responsible for installation, monthly monitoring, maintenance, and licensing fees. Fee amounts may vary depending on the provider and eligibility for financial assistance programs.

Some individuals may qualify for reduced costs based on income.

Why Legal Guidance Matters

Ignition interlock requirements can be triggered at different stages of a DUI case — including after arrest, after conviction, or as a condition of reinstatement.

Understanding when an IID is required, how long it must remain installed, and how it interacts with license suspension rules is critical.

If you are facing DUI charges in Seattle and have questions about ignition interlock requirements, contact our office to discuss your options.