Wisconsin Ignition Interlock Device

Drunk driving defense attorney Dan Skarie will guide you through finding an ignition interlock device installation center, abiding by the IID restrictions in your case, and exempting any necessary vehicles.


What is an IID (Ignition Interlock Device)?

An Ignition Interlock Device, IID, is a small handheld breath testing device that requires the driver to provide a sober breath sample to start your car’s ignition. Additional random breath samples will also be required periodically while the vehicle is in motion. Failure to provide a sample, or a breath result over a certain BAC level (typically .02) will result in the sounding of alarms that require the driver to pull over. The Ignition Interlock Device stores all information and relays it to law enforcement.

Why would I need an ignition interlock device, and for how long?

The length of the IID requirement varies from case to case. Please visit the OWI Penalties page of this website for specific information concerning each level of drunk driving offense.

How long must I use an ignition interlock device?

IID punishments range from 1 year to the duration of license revocation.


What vehicles will need the ignition interlock device installed?

A convicted defendant must install an IID on every vehicle the defendant owns or operates. It is illegal for an offender required to have the device to operate any vehicle unequipped with an IID. A judge may permit a Wisconsin OWI defendant in certain circumstances to use a car that is not equipped with an IID device so long as the judge signs an exemption order. 


Where would I get an ignition interlock device installed?

You will find IID service centers located throughout Wisconsin. The cost of installation and the accompanying monthly payments are the responsibility of the offender for the duration of the IID order. Attempts to tamper or circumvent the IID may result in the imposition of further penalties.


How do ignition interlock devices work?

​The driver must provide a sample before the vehicle starts. If the driver’s breath contains a measurable amount of alcohol (usually .02), the interlock device prevents the engine from starting. Once the driver provides an alcohol-free sample, the engine will start. The IID device will request additional alcohol-free tests at irregular periods while the vehicle is running. So not only do you have to blow to start the car, but you also have to blow periodically to keep the car running. The intention is to prevent a sober person from starting the vehicle for a drunk driver.

How much does an ignition interlock device cost?

Ignition Interlock Devices must be purchased or rented from private companies, and usually cost anywhere from $65 to $100 or more a month. Some companies charge additional fees for installation, and often a deposit is required. Additional fees may apply to maintenance and calibration, as well as transmittal of the information to the DMV.  DUI offenders that are ordered by the court to install the device, unless exempted in full or in part by a judge, must pay their interlock costs.


If you have questions regarding an ignition interlock device, please contact OWI defense attorney Dan Skarie today.



The materials available at this web site are for informational purposes only and not for the purpose of providing legal advice. You should contact an attorney to obtain advice regarding any particular issue or problem. Use of and access to this Web site or any of the e-mail links contained within the site do not create an attorney-client relationship between Vanden Heuvel & Dineen, S.C. and the user or browser. The opinions expressed at or through this site are the opinions of the individual author and may not reflect the opinions of the firm or any individual attorney.