Washington Ignition Interlock Device (IID) & License (IIL)

An Ignition Interlock Device (IID) is an electronic breathalyzer installed in your vehicle’s dashboard. To start the engine, you must provide a breath sample. If the device detects a breath alcohol concentration of 0.04 or higher, the vehicle will not start. The device will also require random “rolling retests” while you drive.

 

When Is an IID Required in Washington?

Under RCW 46.20.720, you are required to install an IID if you have:

Important — Work Vehicles: The IID must be installed on every vehicle you drive. If you operate a vehicle owned by your employer for work purposes, you may qualify for the Employer Exemption by submitting a Declaration of Employer form to the DOL. Note that on a first offense, there is a 30-day waiting period before the employer exemption takes effect.

How Long Does the Requirement Last?

The duration of your IID restriction depends on your prior history under RCW 46.20.720(3)(c):

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

These tiers apply to DUI convictions, Physical Control convictions, and Deferred Prosecution participants alike. If your prior conviction was originally charged as a DUI, but was amended to a lesser charge like Reckless Driving or Negligent Driving, it does not count for purposes of this calculation. For instance, If your prior conviction was originally charged as a DUI but amended to a lesser charge like Reckless Driving or Negligent Driving, it does not count as a prior IID restriction for purposes of this tier calculation. (Note: amended priors can still count as ‘prior offenses’ for DUI sentencing purposes under RCW 46.61.5055 — that’s a separate analysis we can walk you through.)”

When does the clock start? Your IID time begins when the device is installed and the installation is confirmed with the DOL — not when the court orders it. Every day you delay installation is a day added to the back end of your restriction. This is the single most common and costly misunderstanding clients have.

The 180-Day Compliance Rule You cannot remove the device until you have completed the final 180 consecutive days of your restriction period without a violation. Violations include attempting to start the vehicle with a BAC of 0.04 or higher, failing a rolling retest with a BAC of 0.020 or higher, missing a random retest, or tampering with the device. Even one qualifying violation in the final stretch resets the 180-day clock.

Day-for-Day Credit Under RCW 46.20.720(5), if you installed an IID before your conviction — for example, as a pretrial release condition or after losing a DOL hearing — you generally receive day-for-day credit toward your post-conviction restriction period, dating back to the incident. Many clients don’t realize this credit exists, and it can shave months off the back end. This is one of the first things we look at when we take on a DUI case.

Note on License Suspensions vs. IID Restrictions

It’s important to understand that your license suspension and your IID restriction are two separate timelines governed by different statutes. A breath test refusal, for example, triggers a longer administrative license suspension under Washington’s implied consent law (RCW 46.20.3101) than a failed test does — but the IID restriction period itself is still based on the 1/5/10-year tiers above. We can walk you through how both timelines apply to your specific case.

Talk to a Washington DUI Lawyer

The IID and licensing rules are technical, the deadlines are short, and the consequences of getting them wrong compound quickly. If you’re facing a DUI in Clark County or anywhere in Southwest Washington, call us for a consultation — we’ll walk through your timeline, your credit options, and your strategy for minimizing the time you spend with a device on your dashboard.