Washington IID Guide: Rules, Costs, and How to Stay Compliant

A DUI conviction in Washington can result in more than fines and potential jail time—it may also require installing an Ignition Interlock Device (IID) in your vehicle. For many people, this requirement is unexpected, expensive, and frustrating.

Ignition Interlock in Washington: Costs & Requirements

But whether you're required to get an IID or choose to install one to regain driving privileges, understanding how the system works is key.

This guide explains:

  • When an IID is required in Washington
  • How the device works
  • The costs and obligations associated with an IID
  • How to avoid violations that could extend your restriction period

What Is an Ignition Interlock Device?

An ignition interlock device (IID) is a breathalyzer installed in a vehicle that prevents the engine from starting unless the driver provides a breath sample free of alcohol.

Even after starting the car, the device requires random "rolling retests" to ensure the driver remains sober.

When Is an IID Required?

In Washington, an IID may be required in several situations:

  • DUI Conviction – Mandatory for anyone convicted of a DUI, even for a first offense.
  • Deferred Prosecution – An IID is required if you enter Washington’s deferred prosecution program.
  • License Reinstatement – If your license was suspended due to a DUI, an IID may be your only way to drive legally.
  • Repeat DUI Offenses – A second DUI conviction comes with longer IID requirements and stricter monitoring if you previously had a one-year requirement
  • Pretrial Release Conditions -- In some cases, the court may order you to install an IID to stay out of jail while your case is pending.

Washington law requires drivers to install an IID for a minimum of:

  • One year for a first-time DUI conviction
  • Five years for a second DUI conviction if you previously had a one-year requirement
  • Ten years for a third DUI conviction if you previously had a five-year requirement

Even if your conviction was pleaded down to a lesser charge (such as reckless driving or negligent driving), you may still be required to install an IID.

How Does an Ignition Interlock Device Work?

Once installed, an IID requires a breath test before the car will start.

Key Features of IIDs

  • Initial Test – You must blow into the device before starting the engine. If alcohol is detected above 0.025 BAC, the vehicle will not start.
  • Rolling Retests – While driving, the IID will randomly require another breath test to prevent someone from having another person blow into the device at startup.
  • Data Recording – Every breath test is recorded and sent to Washington State’s Department of Licensing (DOL) and your monitoring agency.
  • Tamper Detection – Any attempt to disable or remove the device is reported and could result in additional penalties.

If you fail a rolling retest while driving, the car won’t shut off, but the device will log the violation and may trigger alarms (horn honking, flashing lights) until the vehicle is stopped.

Costs & Fees of an IID in Washington

The costs of an IID add up quickly. While the state allows you to drive with an IID legally, it does not pay for the device—you do.

What You Can Expect to Pay

  • Installation Fee: $75 – $150
  • Monthly Lease Fee: $60 – $100
  • Maintenance & Calibration: $15 – $25 per month
  • Removal Fee: $50 – $100

Over the course of a year, the total cost of an IID can exceed $1,000.

Washington offers a financial assistance program that may cover part of the cost for those who can't afford an IID, but eligibility is limited.

Common Ignition Interlock Violations & Consequences

Washington tracks every IID violation through its reporting system. A single violation can lead to an extension of your IID requirement or even a license suspension.

Common Mistakes That Can Get You in Trouble

  • Failing a Breath Test – Any BAC over 0.025 is logged as a violation.
  • Missed Rolling Retests – Ignoring a retest while driving can trigger alarms and count as a failed test.
  • Tampering with the Device – Trying to remove, disable, or trick the IID is a criminal offense in Washington.
  • Missed Calibration Appointments – IIDs must be regularly calibrated (usually monthly). Missing an appointment can result in your license being suspended again.

How an Attorney Can Help You Handle IID Requirements

Avoiding Violations & Extensions

A lawyer can also help prevent IID-related violations from affecting your ability to drive. If you get flagged for a violation, an attorney can:

  • Challenge the violation if it was due to a device malfunction
  • Help prevent an extension of your IID period

Take Control of Your DUI Case – Contact Knauss Law Today

An Ignition Interlock Device is more than just an inconvenience—it’s a financial burden, a legal liability, and one more way the state keeps tabs on you after a DUI conviction.

If you’re facing DUI charges or an IID requirement, don’t go through it alone. Knauss Law can help you challenge unfair penalties, avoid mistakes, and fight for the best possible outcome.

Call today and get back on the road—without unnecessary penalties.