Interlock Program in WA

By James Stevens, Director and Solicitor, Go To Court Lawyers. Last reviewed 14 April 2026.

The Alcohol Interlock Program in Western Australia is a restricted driving program for those who have been convicted of serious or repeat alcohol-related driving offences. It aims to improve road safety in the state by preventing drivers from operating their vehicle while over the prescribed blood alcohol limit, and by channelling them into assessment and treatment programs.

The program is governed by the Road Traffic Act 1974 as amended by the Road Traffic Amendment (Alcohol Interlocks and Other Matters) Act 2015.

When is an interlock program ordered?

A driver will be ordered into the interlock program in WA if they are convicted of:

• driving under the influence – first offence
• failing or refusing to provide a breath, blood or urine sample to police – first offence
• dangerous driving causing death – first offence
• dangerous driving causing bodily or serious bodily harm while under the influence – first offence
• any second or subsequent drink driving offences committed within five years.

Are there any exemptions?

Exemptions to the program are few. However, a person may be exempted from the program if:

• they live in excess of 150klms from an approved technician, or
• the offence committed is one of refusing a breath sample and they can provide medical evidence that they are not physically able to supply the requisite volume of breath.

What does the interlock program require?

If you have committed one of the relevant offences and are ordered to participate in the program, to be able to drive, you must have your vehicle – whether a car, motorcycle, truck, or another vehicle – fitted with an interlock device. You must not drive any vehicle other than the one that has been fitted with the device while in the program.

The device must be fitted by an approved technician, and you are then required to have it serviced and checked, and the data downloaded every 30 days. All costs are your responsibility, including the cost of removing the device.

Once the device has been fitted, you will be granted an extraordinary licence which includes an interlock condition. You cannot activate the vehicle until you have provided a breath sample registering a blood alcohol content (BAC) of less than 0.02. Readings above this point will lock the vehicle and the breach will be recorded. Whenever a reading over the limit is recorded, it will be presumed that you were the one blowing into the device. You will also be required to provide breath samples at random intervals over the course of a journey.

You must not tamper with the device, or attempt to circumvent it, and you must not allow anyone else to do so.

Before you can exit the program, you must show that you can separate your drinking and your driving for the period for which you have been disqualified – a minimum of 180 consecutive days.

How long will I be on the interlock program in WA?

The duration of your participation in the interlock program in WA is dependent upon the type of licence you hold, the offence committed, and the disqualification period imposed by the courts.

At a minimum, for those who have not previously held an extraordinary driver’s licence, the program will last for six months. Those who have been disqualified from driving but have been granted an extraordinary licence must participate in the program for the period of time for which they have been disqualified from driving (a minimum of six months).

In some cases, a driver may be permanently disqualified from driving but permitted to hold an extraordinary licence. In these cases, the driver must participate in the program for a minimum of three years.

How much will it cost me?

Bearing the cost of the interlock program in WA is the responsibility of the driver. It is likely to cost from $1,600 to $2,200 though some variation is likely depending on factors such as location and distance from approved technicians. You may be able to access a concession rate reducing the monthly cost by $50.

The pricing is comparable to programs in other Australian states and territories. For example, interlock orders in NSW currently cost drivers approximately $2,200.

What happens if I don’t obey the order?

If you drive a vehicle that does not have an interlock device installed while you are subject to the interlock program, you will have committed an offence as you will be driving unlicensed. You may be fined, face further disqualification from driving, or you may be imprisoned.

If you do not take your vehicle to have the device serviced at the required time, the device will disable your vehicle. The only way to unlock the device is for a technician to attend. This will incur extra costs for which the driver will be responsible.

If the driver records a BAC of 0.02 or more, the interlock device will prevent the vehicle from starting and the reading will be recorded.

Failure to comply with any of the conditions may result in a longer period of restricted driving. You may also have to participate in an assessment and treatment program with the WA Mental Health Commission.