Western Australia recorded 177 road deaths in the 12 months to April 2026, according to the National Road Safety Data Hub. Drink driving remains a leading contributor to that toll. The WA Alcohol Interlock Scheme was introduced to give people convicted of drink driving a structured, evidence-based path back to safe and legal driving, through a mandatory, user-pays, performance-based programme.
This guide covers everything you need to know about WA alcohol interlock rules: who must participate, exactly how the scheme works, how long it takes, what the device records, what it costs, and who qualifies for an exemption. Last updated June 2026.
Who Must Join the WA Alcohol Interlock Scheme
The WA Alcohol Interlock Scheme is mandatory for anyone convicted of an eligible drink-driving offence on or after 24 October 2016, under the Road Traffic Act 1974. The scheme applies regardless of whether you receive a custodial sentence; the conviction itself triggers the interlock condition.
| Offence Category | BAC / Threshold | Mandatory? |
|---|---|---|
| Driving under the influence (DUI) | Any level | Yes, all convictions |
| Dangerous driving causing death or grievous bodily harm (alcohol-related) | Any level | Yes, all convictions |
| Dangerous driving causing bodily harm (alcohol-related) | Any level | Yes, all convictions |
| Failure to provide breath, blood or urine sample | N/A | Yes, all convictions |
| Driving with BAC of 0.08% or above | 0.08%+ | Yes, if prior conviction within 5 years |
| Driving with BAC of 0.05% or above | 0.05%+ | Yes, if prior conviction within 5 years |
| Driving with BAC of 0.02% or above | 0.02%+ | Yes, if prior conviction within 5 years |
Source: Department of Transport WA, Road Traffic Act 1974
One important distinction: a first-time offence at a BAC between 0.05% and 0.08% does not automatically trigger the mandatory scheme unless you have a prior conviction within the preceding five years. If you are uncertain whether your conviction falls within the mandatory scheme, confirm directly with DoT WA or your legal representative.
People whose offences occurred before 24 October 2016 were not covered by the mandatory scheme, and earlier convictions may be subject to voluntary interlock conditions under separate arrangements. If you choose not to participate in the scheme after receiving an interlock condition, you can only legally drive a vehicle that already has an approved interlock installed by an accredited service provider.
How the WA Scheme Works: Step by Step
The WA scheme follows a clear sequence from conviction to the removal of licence conditions. Each step must be completed in order before you can move to the next.
Step 1: Court conviction and interlock order issued. The court records the conviction, and your licence is cancelled. The mandatory interlock condition attaches automatically to any new licence you are granted.
Step 2: Apply for your driver's licence at a DoT WA service centre. Bring your proof of identity. The interlock condition will be endorsed on the licence at this stage, and you will be known as an interlock-restricted driver.
Step 3: Pay the DoT licence condition fee. The current fee is $231.40, payable to the Department of Transport and Major Infrastructure (Driver and Vehicle Services) upon grant of the interlock-restricted licence.
Step 4: Have an approved interlock device installed by an accredited service provider. You cannot legally drive yourself to the installer. A friend or family member must take you to the installation appointment. Once an approved device has been installed, you can resume driving legally. Affordable Interlock Systems installs the ALCOLOCK LR, one of the approved devices for use under the WA scheme.
Step 5: Attend monthly inspections. Every month, you must present your vehicle in person for a data download and calibration check. Monthly attendance is a requirement of the scheme, not a recommendation. Failing to attend is recorded as a breach.
Step 6: Complete 180 consecutive days without any breach events. The final stage of the scheme requires you to demonstrate separation from drinking-and-driving behaviour for a continuous 180 days immediately before exiting. This period must be completed without any breach, including failed breath tests, missed service appointments or device tampering.
Step 7: Apply to DoT WA for condition removal. Once the 180-day clean record is confirmed, DoT WA removes the interlock condition from your licence and notifies you in writing. You can then have the device removed by your accredited service provider.
How Long Is the WA Interlock Period?
The minimum interlock period reflects the disqualification period attached to your offence, typically at least six months for a first conviction. More serious or repeat offences attract longer mandatory periods. A high-range or repeat offender may face a minimum period of 12 months or more.
The exit from the scheme is performance-based, not purely calendar-based. You must complete the 180-day clean-record window in the period immediately before exiting, regardless of how long you have been on the scheme overall. If a breach event occurs during the 180-day window, the clean-record clock resets, and you must start the 180 days again from scratch.
What the Device Records (and What to Avoid)
The alcohol interlock records every breath sample you provide, every start attempt, every rolling test during a journey, and any attempt to tamper with the device or its wiring. This data is downloaded at each monthly service appointment and assessed by DoT WA. The device will prevent the vehicle from starting if it detects a BAC of 0.02% or higher in the provided sample.
While the device threshold is 0.02%, your legal obligation as an interlock-restricted driver is a zero BAC at all times while driving. The device has a technical threshold; the law requires zero. These two figures are not the same.
To avoid false readings, do not use mouthwash or alcohol-based mouth spray before testing. Avoid eating immediately before providing a sample. Cigarette smoke does not trigger the device. If you are uncertain whether a medication contains alcohol, check with your pharmacist before use.
Violations that constitute a breach of the scheme include: a positive BAC reading at or above the threshold, a missed rolling test while driving, a missed monthly service appointment, or any tampering with the device or vehicle wiring. A breach event can extend your total time on the scheme by resetting the 180-day clean-record requirement.
Costs for WA Interlock Participants
The WA scheme is user-pays. All costs associated with the device are the participant's responsibility, covering installation, monthly rental, servicing and removal.
| Cost Item | Estimated Amount |
|---|---|
| DoT WA licence condition fee | $231.40 |
| Minimum 6-month total (device costs) | $1,600 (DoT WA estimate) |
| Installation | Around $200 to $350 |
| Monthly service appointment | Around $100 to $150/month |
| Estimated annual device cost | Around $1,300 to $2,100 |
The $1,600 minimum six-month total is the official DoT WA estimate and is subject to change. Contact Affordable Interlock Systems directly for current WA pricing. If you are experiencing financial hardship, contact the Department of Transport WA to ask about available support options.
WA Interlock Exemptions: Who Qualifies?
Exemptions from the WA Alcohol Interlock Scheme are available in two circumstances, and both are formally assessed.
Distance exemption: If you live more than 150 kilometres (measured in a straight line) from the nearest accredited service provider, you may qualify for a distance exemption. DoT WA assesses this automatically when your interlock-restricted licence is granted. If you later move to a qualifying remote area, you can apply using Form E3 with evidence of your new address.
Medical exemption: If you have a certified medical condition that prevents you from physically operating the device, you can apply for a medical exemption. Your GP or medical specialist must complete the relevant sections of Form E3 and submit supporting documentation to DoT WA. The department reviews the recommendation and advises you in writing.
Do not assume eligibility without applying formally. The exemptions are not discretionary, and informal guidance from third parties is not a substitute for the official assessment process. Note also that if you are granted a distance exemption and an accredited service provider later opens in your area, your exemption may be removed.
Frequently Asked Questions About WA Alcohol Interlock Rules
Who is exempt from alcohol interlock in WA? Two categories qualify: people who live more than 150 kilometres (straight line) from the nearest accredited service provider, and people with a certified medical condition that prevents them from operating the device. Both require a formal application to DoT WA on Form E3. Exemptions are not granted automatically and are strictly assessed.
How much does an alcohol interlock device cost in WA? The DoT WA estimates a minimum total cost of $1,600 over six months, covering installation, monthly rental, servicing and removal. Installation starts at $350, and monthly service appointments from $150. The $231.40 DoT licence condition fee is payable separately. Contact your accredited service provider for current pricing.
Where can I find alcohol interlock installers in Perth? Affordable Interlock Systems operates accredited ALCOLOCK installation and servicing centres across Western Australia. Find your nearest WA location to book your installation appointment.
What is a breach of the alcohol interlock condition? A breach includes recording a BAC at or above 0.02% on a breath test, missing a rolling test while driving, failing to attend a monthly service appointment, or tampering with the device or vehicle wiring. A breach event resets your 180-day clean record requirement.
Can I drive a different car without an interlock if I am on the WA scheme? No. As an interlock-restricted driver, you may only drive vehicles fitted with an approved alcohol interlock installed by an accredited service provider. Driving any vehicle without an approved interlock is an offence under the Road Traffic Act 1974, carrying penalties including fines, further disqualification and vehicle impoundment.
Getting Started with the WA Scheme
The WA Alcohol Interlock Scheme is a structured programme with a clear exit: demonstrate that you have separated drinking from driving for 180 continuous days, meet all the scheme requirements, and the interlock condition is removed. For the vast majority of participants, that is exactly what happens.
Affordable Interlock Systems is an accredited service provider under the WA Alcohol Interlock Scheme, installing and servicing the ALCOLOCK LR device. Our WA service centres operate to AS 3547:2019, the Australian Standard for breath alcohol testing devices. To learn more about how alcohol interlock devices work, read our guide on how alcohol interlocks work to make Australian roads safer.
Call 1800 252 656 to book your WA installation or to ask about monthly servicing options across Western Australia.
For official scheme information, visit the Department of Transport WA Alcohol Interlock Scheme page or download the WA Alcohol Interlock Scheme Participant Guide (Department of Transport WA, updated May 2026). For counselling and support during the programme, Holyoake provides dedicated alcohol interlock scheme support for participants and their families across Perth and WA's Wheatbelt.
