Simple Interlock – Ignition Interlock Company (United States)

Simple Interlock is a US ignition interlock company. It is certified by the Washington State Patrol (Simple Interlock LLC) and appears on the Texas Department of Public Safety list of approved interlock manufacturers as Simple Interlock Co. (December 2025).

Contact

Phone: 1-844-432-4775 (number listed by the Washington State Patrol).

Before you book

Confirm certification in your state, ask about service centre locations, and get a written quote for every fee in your program.

What an interlock program usually costs

Interlock programs are paid by the driver. Most providers charge an installation fee, a monthly lease and monitoring fee, a fee at each calibration visit, and a removal fee at the end of the program. Prices differ by state and by company, and some states offer reduced-cost or indigent programs for drivers who qualify. Ask for every fee in writing before you sign, including any charges for missed appointments, violation resets or lockout service calls.

Service visits and calibration

After installation you return to a service centre on a set schedule so the device can be calibrated and its data downloaded and sent to your state agency. Missing a visit can lead to a lockout or a report of non-compliance, so choose a provider with a service centre close to where you live or work.

How ignition interlock works in the United States

An ignition interlock device (IID) is a breath-alcohol tester connected to your vehicle’s ignition. You blow into it before starting the engine and at random times while driving. If it detects alcohol, the vehicle will not start and the event is recorded and reported to the agency supervising your case.

Each state certifies which interlock companies may install devices, and requirements vary by state. Many states require an interlock after a DUI or DWI conviction, for a restricted licence during a suspension, or for repeat and high-BAC offences. Your court order or motor vehicle agency letter tells you what applies to you.

Questions to ask before you book

• Is the company certified in my state, and is the device on the state’s current approved list?
• Where is the nearest service centre, and is mobile installation available?
• What are the installation, monthly lease, calibration and removal fees, and do I qualify for a reduced-cost program?
• How often do I need to come in for calibration, and what support is available for lockouts?

Compare other providers

Most states certify several interlock companies, so it pays to compare price, service centre locations and support before you choose. See our United States page for more certified providers.

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