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Ignition Interlock Device FAQs | Wisconsin OWI Laws

6 FAQs About Ignition Interlock Devices in Wisconsin

An ignition interlock device (IID) is often a penalty for OWI in Wisconsin, particularly if it is the driver’s second OWI or higher or if the driver had a high BAC level. While IIDs used to be saved for only the most egregious of OWI violations, the technology has become much more accessible. As a result, IIDs are now mandatory for certain OWI convictions in the state. Below, we provide answers to six of the most common questions drivers have about ignition interlock devices.

Ignition Interlock Device FAQs

  1. What is an Ignition Interlock Device?

The intention of the IID is to inhibit an inebriated driver from getting behind the wheel, preventing an incident before it has a chance to start. These devices are installed on the vehicle dashboard and operate much like a breathalyzer. The driver must breathe into the mouthpiece so that the device can measure the BAC level of the breath sample. If the sample registers below the programmed acceptable BAC level, the device allows the engine to start. If the breath sample is higher than the allowed BAC level, the engine is locked and cannot be driven.

Modern IIDs also require drivers to provide periodic samples once the engine has been unlocked and while the vehicle is in use. This helps deter drivers from drinking and driving or leaving the ignition on while they stop somewhere to get a drink in an attempt to circumvent the device. If the breath sample is not provided or registers at an unacceptable level, the device records the data, emits a warning to the driver that they are not permitted to drive, and sounds an alarm until the ignition is turned off.

  1. Who Must Have an IID installed?

In 2010, Wisconsin state law was changed to require an IID to be installed when:

  • A driver was convicted of a second OWI or greater.
  • A driver registers a BAC of .15 or higher on their first offense.
  • A driver refuses a breath or blood test at a traffic stop.

Every vehicle registered to the driver must have an ignition interlock device installed and the offender is not allowed to drive any vehicle without an IID installed as long as their driving privileges are restricted.

  1. How Long do IIDs Remain Installed in the Vehicle?

In Wisconsin, IIDs must remain installed for at least one year, but each case is different and the total time of installation depends on the specific penalties, suspensions, and driving restrictions placed on the offender. Restrictions usually begin immediately. Anyone eligible for an operating privilege or occupational license must have the IID installed when their driving privileges are reinstated.

Failure to install the device, remove, disconnect, or disable it will result in a six-month extension, fines, and possible jail time.

  1. Can I Just Wait Out the IID Order?

No. If you have been ordered to install an IID as part of your OWI penalties, you must comply with the order. It is always possible that you choose not to drive during the time that you must have the IID installed, but the clock on the IID order begins as soon as the DMV issues your license to you. When that happens, your license will indicate restrictions such as Class D with IID requirements.

  1. How Much Does it Cost?

IID purchase and installation costs are the responsibility of the driver. Costs in Wisconsin are typically

$1,200-$1,400 per year, per vehicle. The state does have a low-income offender program in which qualified drivers may qualify for a 50% reduction in installation and removal costs and pay half the cost of the daily fee per vehicle.

  1. Where do I get an Ignition Interlock Device?

Local service centers are certified to install and maintain IIDs. The Wisconsin DMV also maintains a list of certified installers and associated IID costs, here.

Help Is Available for Those Facing IID Restrictions

Eisenberg Law Offices helps Wisconsin drivers build OWI defense strategies that can reduce charges and help avoid IID restrictions. If you are facing an OWI with the possibility of having an Ignition interlock device installed in your vehicles, contact our Madison law firm to schedule a free case consultation with an OWI defense attorney. We will examine the facts, explain the charges against you, and advise you of your options.

Contact Eisenberg Law Offices at 608-256-8356 or



Eisenberg Law has successfully represented our clients in thousands of Personal Injury, Criminal Defense and Family Law Cases during our 30-plus years in business.