An Ignition Interlock Device (IID) is a handheld breath-testing device that is connected to the vehicle's ignition, horn, and headlights. To start the vehicle, a driver must blow into the device without registering a blood alcohol concentration (BAC). Some IID units are equipped with camera and GPS.

If you are seeking a court-ordered Limited Driving Privilege (LDP) or court-ordered reinstatement because your Missouri driving privilege is currently under a 5- or 10-year denial, you are required to install an IID equipped with camera and GPS.

If your Missouri driving privilege is not currently under a 5- or 10-year denial, the camera and GPS features are not required unless ordered by the court.

After installation of the IID, you are required to report to a certified IID installer each month for maintenance to ensure the device is working properly. The manufacturer will also download information from the device to create a "monthly monitoring report" to check for any violations you may have.

NOTE: In addition to the IID requirements explained above, a court may impose other requirements, such as an IID period longer than six months. If you are convicted of failing to have an IID installed as required by law, your driving privilege will be revoked for one year. A second offense requires driving privileges to be denied for five years.

If your monthly monitoring reports show a violation of the device, you will be required to maintain the device on your vehicle for an additional period of time:

  • An additional 30 days if you were issued an Immediate 90-Day Restricted Driving Privilege (RDP); or
  • An additional 6 months if you were required to install the IID for reinstatement of your Missouri driving privilege.

A violation is defined, by law, as any incident of device tampering, circumvention, or confirmed breath alcohol level of .025 percent or more. Sections 302.060; 302.304; 302.525; 577.041, RSMo; and 7 CSR 60-2.010.

If you have any questions or concerns about IID violations reported to the Department by the IID manufacturer, you must contact the manufacturer.

Failure to maintain the device while driving on a Limited Driving Privilege (LDP) will result in a termination of the LDP. The IID must also be maintained for the entire period of your Limited Driving Privilege (LDP). Before you may resume driving, you must install or have the device serviced, and then apply for (and be granted) a new LDP.

Failure to maintain the device while driving on a Restricted Driving Privilege (RDP) will result in a termination of the RDP. Before you may resume driving, you must install or have the device serviced and then contact the Department of Revenue for assistance.

Failure to maintain the device during the six-month period (184 days) after reinstatement will result in a re-suspension of driving privileges for the remainder of the six-month period plus assessment of an additional six-month period of IID requirement. You will then be required to do the following before your Missouri driving privilege can be reinstated:

  • Have the IID serviced or reinstalled (the certified installer will send proof of service or reinstallation to the Driver License Bureau); and
  • Pay a $20 reinstatement fee.

It is possible to prevent the suspension from going into effect if you submit and the Department timely receives acceptable proof that the IID has been installed or serviced as required by law.

You should not remove the device until you verify with the Department of Revenue that you are allowed to do so. Early removal of the device may result in the re-suspension of your driving privilege and an extension of the period that the IID must be maintained.

The manufacturer of the device is required to electronically notify the Department if you maintained your device for the required length of time without violations. Once the Department has received certification from the manufacturer, you may remove your IID without penalty.

The IID must be certified and approved by the Missouri Department of Transportation (MoDOT).

For information about approved devices, visit the MoDOT website or call 800-801-3588.

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