Ignition Interlock Program

What you need to know regarding the Ignition Interlock Program.

RSA 259:43-a defines "Ignition interlock device" as a system or device that connects a breath analyzer to a motor vehicle's ignition system. The analyzer measures the concentration of alcohol in the breath of any person who attempts to start the motor vehicle by using the ignition system. The device prevents the vehicle from starting unless the person provides a breath sample with a concentration of alcohol that is below a preset level.

If you have received notification from the DMV that you are required to have an ignition interlock device installed, you must present a Certificate of Installation issued by an approved vendor to the Bureau of Financial Responsibility at the Concord DMV office.

For more information related to the offenses or circumstances that someone shall be required to have an ignition interlock device installed, please refer to New Hampshire laws RSA 265-A:36 and 265-A:36-a.

Approved Vendors

Currently, there are five vendors authorized to install these devices:

License Restriction

Once the Certificate of Installation has been presented to the Bureau of Financial Responsibility, you will be required to have an Alcohol Interlock Device restriction added to your driver license.


Unless otherwise indicated by the court, the duration that the device is required to be installed would be calculated from the date of restoration of the NH license/operating privilege.

Transferring from Out of State

If you are transferring your license from another state and you have an Alcohol Interlock Device restriction, please be advised that this restriction will transfer to your New Hampshire driver license.

Removal of Restriction/Device

The law which defines the Ignition Interlock Device Removal Protocol (RSA 265-A:38-a)requires that prior to the removal of an Ignition Interlock Device from a vehicle, the Ignition Interlock Device provider shall obtain a certificate of removal from the department's interlock coordinator.