What Is an Ignition Interlock Device and How Does It Affect My Missouri DUI Case?

If you’ve been arrested for DUI/DWI in Missouri, one of the conditions for keeping or regaining your driver’s license may be installing an Ignition Interlock Device (IID) in your vehicle.

This small device has a big impact, it can mean the difference between being able to drive and being stuck on the sidelines for months or years.

At KC Defense Counsel, our experienced Missouri DUI and DWI defense lawyers in Kansas City help clients navigate Missouri’s DUI laws, including the IID requirement, so they can get back on the road legally and quickly.

WHAT IS AN IGNITION INTERLOCK DEVICE?

An Ignition Interlock Device, or IID, is a breath-testing unit installed in your car that prevents the engine from starting if it detects alcohol on your breath.

Here’s how it works:

Before starting your car: You must blow into the device. If your BAC is above the preset limit (usually 0.025%), the engine won’t start.

Rolling retests: While driving, you may be prompted to blow into the device again to ensure you haven’t consumed alcohol after starting the car.

Data recording: The IID logs every test, pass/fail result, and any attempt to tamper with the system. This data is reported to the Missouri Department of Revenue and sometimes the court.

WHEN IS AN IDD REQUIRED IN MISSOURI?

Missouri law may require an IID for:

First-time DUI offenders seeking Limited Driving Privileges (LDP) during suspension
Refusal cases (refusing a breath/blood test) when applying for LDP
Repeat DUI offenders
High BAC offenders (0.15% or above)
Cases where the court orders IID as a condition of probation

The length of the IID requirement depends on your offense and history, anywhere from 6 months to several years.

HOW LONG WILL HAVE TO USE AN IID?

Typical timelines:

First Offense DUI/DWI: 6 months to 1 year

Refusal or Repeat Offenses: 1 to 2 years (sometimes longer)

Serious Cases: Can extend up to 5 years in rare situations

HOW MUCH DOES AN IDD COST AND DOES THE STATE OF MISSOURI PAY FOR IT?

Unfortunately, the costs are entirely your responsibility and usually include:

Installation fee ($75–$150)
Monthly rental fee ($60–$90)
Calibration and maintenance costs

Over a year, IID costs can add up to $1,000 or more — one of the many reasons fighting a DUI charge early is so important.

WHAT HAPPENS IF YOU VIOLATE IID RULES IN MISSOURI?

Violations can include:

Attempting to start your car after drinking
Missing rolling retests
Tampering with the device
Failing to report for scheduled calibration

Penalties for violations can include:

Extension of your IID period
License suspension or revocation
Probation violations and possible jail time

HOW AN EXPERIENCED KANSAS CITY DUI/DWI ATTORNEY CAN HELP

If you’re facing DUI/DWI charges in Missouri, call KC Defense Counsel immediately. Our skilled and affordable Kansas City DUI lawyers can:

Fight to avoid an IID requirement altogether by challenging your DUI case
Help you apply for Limited Driving Privileges as soon as possible
Guide you through compliance so you don’t risk losing your driving rights
Defend you against alleged IID violations

CALL KC DEFENSE COUNSEL AND LET US BEGIN BUILDING YOUR DEFENSE

An IID may be better than not driving at all, but it’s still expensive, restrictive, and embarrassing. With the right defense strategy, you may be able to avoid it entirely.

If you’re facing criminal DUI charges in Missouri, don’t leave your future to chance. The stakes are too high and the legal system too complex — to navigate alone. An experienced Kansas City criminal defense attorney can mean the difference between a conviction and a second chance.

At KC Defense Counsel, we bring the knowledge, strategy, and relentless advocacy you need to protect your rights and your freedom.

Cities we serve: Adrian, Archie, Bates City, Belton, Blue Springs, Buckner, Butler, Cameron, Claycomo, Cleveland, Drexel, Fairview, Ferrelview, Gladstone, Grain Valley, Grandview, Greenwood, Houston Lake, Independence, Kansas City Missouri, Kearney, , Knob Noster, Lake Lotawana, Lake Tapawingo, Lake Waukomis, Lake Winnebago, Lawson, Lee’s Summit, Liberty, North Kansas City, Oak Grove, Oakview, Parkville, Peculiar,, Platte City, Platte Woods, Plattsburg, Pleasant Hill, Raymore, Raytown, Riverside, Smithville, Sugar Creek, Tracy, Warrensberg, Weatherby Lake, and Weston.

Statewide: Missouri State Highway Patrol and Sheriff Counties we serve: Bates County, Cass County, Clay County, Jackson County, Platte County, Ray County.

Contact our experienced Kansas City criminal defense lawyers near me in Missouri and let us help begin building your defense. Let us help.

Disclaimer: This page is for informational purposes only and does not create an attorney-client relationship. Always consult qualified counsel regarding your unique situation.