Washington Ignition Interlock — Requirements & Costs
When interlock may be required and practical steps.
When Washington requires an IID §46.20.720
minimum 1 year (no prior interlock restriction).
How long the IID must remain installed
1 year with no prior restriction; 5 years after one prior restriction; 10 years after two; extended if a passenger under 16 was in the vehicle.
How the device works in practice
Violations and extensions
Common violations that can extend the IID period or trigger additional consequences:
- Failed startup tests (BAC above threshold)
- Failed rolling retests
- Missed calibration appointments
- Tampering with or attempting to circumvent the device
- Operating a vehicle without an IID when one is required
Costs
IID costs are borne by the offender and include:
- Installation fee
- Monthly monitoring/rental fee
- Removal fee
- Calibration fees (may be included in monthly rental or charged separately)
The IID as a path back to driving
While the IID is a restriction, it is also the mechanism that allows many offenders to resume driving sooner than they would under a full suspension. In Washington, Ignition interlock license (IIL) available immediately with IID installation — allows driving during suspension. Complying fully with IID requirements — no violations, on-time calibration — is the fastest path to full reinstatement.
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Frequently Asked Questions
General answers to common questions. Specific outcomes depend on your facts and timing.
If you have a deadline, court notice, or upcoming hearing, mention it when requesting assistance so timing can be evaluated promptly.

