Definition
An ignition interlock device (IID) is a breath-testing unit wired directly into a vehicle’s ignition. Before the car starts, the driver blows into it. If the device detects breath alcohol content above a preset limit, the engine won’t start. The car also requires random breath samples while driving — called rolling retests — to confirm the driver stays sober throughout the trip.
In Washington, the IID is commonly called a car breathalyzer. The DOL and courts also refer to it as an ignition interlock, an IID, or a breath alcohol ignition interlock device (BAIID).
How It Works
Washington requires an IID for anyone convicted of a DUI or physical control offense, for drivers who enter a deferred prosecution, for some reckless driving convictions, and for any court-ordered IID requirement. Even a first offense mandates installation. Under prior Washington law, a convicted driver could simply choose not to drive. That option no longer exists.
Washington law requires that you use a certified interlock provider. You can’t install a device yourself or buy one off the internet. Approved vendors are listed through the Washington State Patrol. Once installed, the provider submits proof to the DOL. At that point, a driver can apply for an Ignition Interlock License (IIL), which allows them to drive during their suspension period as long as every vehicle they drive has a device installed.
Washington sets the Breath Alcohol Concentration (BrAC) threshold at 0.025. That’s well below the legal driving limit of 0.08. Any failed start attempt or missed rolling retest is recorded and reported to the DOL, and could affect your license status or case outcome. The device can’t be fooled. Tampering is logged, reported, and treated as a criminal offense.
The first DUI usually requires the IID to be installed for one year although there are ways to shorten the requirement. A second DUI within seven years extends the IID requirement to five years and a third conviction means at least ten years with the device.
An SR-22 is required alongside the IID to receive an IIL. If that SR-22 lapses at any point, the DOL again suspends your driving privileges automatically.
Why It Matters
Skipping the IID requirement doesn’t make it go away. Between 2018 and 2025, only 41% of Washington drivers required to install an IID actually did so. The other 59% are still driving without a valid license and risking criminal charges.
The insurance side runs parallel. Many drivers face premium increases of 50% or more after a DUI conviction or IID restriction. Standard carriers often won’t write the policy at all, which means the non-standard market is the only option and that costs more, sometimes significantly.
Getting the device installed and the SR-22 filed is the fastest path back to legal driving. Waiting it out is not.
Talk to an Agent
If you need SR-22 coverage to satisfy an IID requirement in Washington, Mid-Columbia Insurance works with non-standard carriers and files SR-22s directly.
Call (509) 783-5600 or get a quote online.
Identities
- Glossary: Ignition Interlock Device
- Wikipedia: Ignition Interlock Device
- DBPedia: Ignition Interlock Device
- ProductOntology: Ignition Interlock Device
- Wikidata: Q1416572