Alcohol interlocks

Read our legal information about COVID-19 coronavirus.

Alcohol interlocks

An alcohol interlock is a device that measures and records the amount of alcohol on the driver’s breath. It prevents a vehicle from starting if the driver has been drinking alcohol.

The device is fitted to a vehicle and the driver must blow into it before starting the vehicle. The vehicle will not start if there is alcohol on the driver’s breath.

When an alcohol interlock is used

Your vehicle will be fitted with an interlock if your licence was cancelled for drink driving. In most cases a driver can apply to VicRoads for a new licence after they have served the minimum disqualification period. Before VicRoads will issue another licence, the driver will need to:

  • complete a behaviour change program, and 
  • have an alcohol interlock device fitted to their vehicle. 

The interlock licence will last for at least six months. This depends on offence that the driver was disqualified for. 


Before 1 December 2019 many drivers had to attend court to get another licence after it had been cancelled for drink driving. For some of these drink driving offences, the court could choose not to impose an interlock condition. This depended on the kind of offence and when the offence happened. 

A driver whose licence was cancelled for one of these old offences can appeal to the Magistrates’ Court if VicRoads refuses to grant a licence without an interlock condition.  

Alcohol interlock exemption on medical grounds

A driver may to apply for an interlock exemption from VicRoads. They will need to get a report from a registered specialist health practitioner giving details about why their health condition means that they will not be able to use an alcohol interlock. Drivers who are exempt must still have zero BAC when they are driving.

VicRoads may require the person to be tested to see if they are fit to drive at all.

If you do not follow the rules for using your alcohol interlock you could be fined and your interlock licence could be suspended.  

Getting an interlock removed

Before you can have an interlock condition removed from your licence you must serve the minimum interlock period that you were given and follow the rules for using the interlock. 

From 1 December 2019 all drivers must apply to VicRoads to get the interlock removed. 

VicRoads will look at information recorded on your interlock device when they are deciding if you can have the interlock removed. You will need to be able to show that you have separated drinking from driving. The Alcohol Interlock management system (AIMS) stores information about your interlock use including camera images. VicRoads will use this data to decide if you can have your interlock removed. 

Some drivers will need to complete a 2-hour pre-interlock removal behaviour change program before VicRoads will consider removing their interlock condition. 

If you are successful VicRoads will send you an interlock removal authority and a new licence. You will have to show these to the interlock service agent before they will remove the interlock from your vehicle.

Get help

Find out how you can get help with traffic offences.

Was this helpful?