New Hampshire Ignition Interlock Device Laws

In New Hampshire, someone who has been convicted of Driving While Intoxicated may have an ignition interlock device installed in their car in order to get their driving privileges reinstated. In New Hampshire, this can be either mandatory or voluntary, depending on the case.

What is an Interlock Device?

This Ignition-Interlock device is a safety measure that is connected to the dashboard. The device works like a Breathalyzer. When the driver blows into the sensor, it measures the alcohol level to determine whether the car can be driven. In the event that the device detects an alcohol level that is 0.02% or higher, the car will not start. This process takes some time and may be considered as inconvenient, but it can also save lives.

How Do I Find Out Whether I Qualify for the Interlock Device?

In New Hampshire you will need an interlock device if convicted of the following offenses:

  • Aggravated DWI
  • A second or subsequent DWI conviction (RSA 265-A:18)
  • DWI for drivers who are under 21

To get answers regarding your specific case, contact us for a Free Confidential Consultation now by calling 603-537-0700. You may also email us:

Resources: New Hampshire Interlock Device Rules

What are the terms for using the Ignition Interlock Device?

  • By law, the driver has to have the device installed on their primary vehicle
  • Minors with a DWI conviction have the device installed for one year or until their 21st birthday (whichever is longer)
  • When it comes to motorcycles, a restraining device may need to be installed
  • The interlock device that is used must be approved
  • The driver is responsible for any and all fees and/or maintenance.

Additionally, New Hampshire requires the following:

  • The device must be recalibrated every 30, 60, or 180 days as directed
  • The driver has to present the reports from the device to the courts upon request
  • Data from the device must be maintained and available for a minimum of 3 years
  • The driver has to provide any and all certificates of installation

There are penalties and fines associated with the misuse of this device. In some cases, both the driver and passenger may face prosecution. The possible consequences include:

An experienced NH criminal attorney can help you navigate this complicated process to determine your best option.

If you have any questions about this device and whether you are eligible for it, please call us to schedule a free consultation.

Contact us by phone or e-mail

We provide a free 30-minute initial consultation.

Phone: (603) 537-0700


credit card logos