By James Stevens, Director and Solicitor, Go To Court Lawyers. Last reviewed 10 April 2026.
Key points
- The interlock follows every conviction for driving under the influence (including any reading of 0.15 or more), refusing a breath analysis or blood test, and dangerous driving under the influence causing harm.
- After a 0.02, 0.05 or 0.08 offence it applies only if you had another drink driving offence in the 5 years before the conviction. A first 0.08 offence on its own is not an interlock offence.
- The court disqualification cancels your licence, and any licence you are granted afterwards, including an extraordinary licence, carries the interlock condition.
- The condition comes off once the disqualification has ended and you have driven with the device for at least 180 days in a row without a breach. There is no banded 6, 12, 24 or 48-month period.
- Cost: a $231.40 government fee, plus the provider's charges; the Department of Transport estimates at least $1,600 over six months.
- For a lawyer, call 1800 577 015 at any hour: free general legal information, and a 60-minute consultation with a Western Australian lawyer for a fixed $295.
In Western Australia, an alcohol interlock is required after every conviction for driving under the influence or refusing a breath or blood test, and after a lower-range drink driving conviction only where there was another drink driving offence in the previous 5 years; the condition is removed once the driver has completed at least 180 consecutive breach-free days with the device after the disqualification ends.
Checked on 22 October 2026 against the Road Traffic (Authorisation to Drive) Act 2008, the Road Traffic (Authorisation to Drive) Regulations 2014 (regulation 3 and Part 5A), the Road Traffic Act 1974, the Department of Transport's interlock pages and its participant guide (June 2026), and the Road Safety Commission. The scheme applies to offences committed on or after 24 October 2016.
Which offences bring the interlock
| Offence | When the interlock applies |
|---|---|
| Driving under the influence of alcohol, including any reading of 0.15 or more | Every conviction |
| Refusing a breath analysis or blood test (section 67(2)) | Every conviction |
| Dangerous driving causing death, grievous bodily harm or bodily harm while under the influence | Every conviction |
| Refusing a drug test with a breath reading of 0.15 or more | Every conviction |
| Driving at 0.08 or more, at 0.05 or more, or at 0.02 or more for a zero-alcohol driver | Only if you were convicted of another interlock-listed offence committed on or after 24 October 2016 in the 5 years before this conviction |
| Driving with alcohol and drugs, and the lesser drug-test refusal offences | Only with an earlier listed offence in the 5 years before this conviction |
What happens
- Your licence is cancelled by the court disqualification for an interlock offence, not just suspended.
- The condition goes on any later licence. When you are next granted a licence, including an extraordinary licence, the Department of Transport must endorse it with the interlock condition, whatever the court order says.
- The device is fitted by an accredited provider. It stops the vehicle starting at a reading of 0.02 and asks for random re-tests while you drive. Interlock drivers must have zero alcohol. The device is inspected every month.
- Driving without it, or breaking the interlock condition, is treated as driving without authority, and the vehicle can be impounded. Tampering with or getting around the device carries a fine of up to $2,500.
How the condition comes off
- Every period of disqualification has ended; and
- you have driven with the device for at least 180 days in a row, up to the day the condition is removed, without a breach; and
- you have completed any required alcohol assessment and treatment.
- For someone permanently disqualified who holds an extraordinary licence: restricted driving periods totalling at least 3 years.
- The period restarts after tampering, three triggers in one inspection period, or missing more than one monthly inspection.
- If you never present a vehicle with an interlock, the condition stays on your licence indefinitely.
Cost and exemptions
The government fee is $231.40 when the licence with the interlock condition is granted. The accredited provider charges for installation, rental, monthly inspections and removal; the Department of Transport estimates the minimum total at $1,600 over six months, and says the estimate is subject to change. You may be exempt if you live more than 150 km from any accredited provider, or if a medical condition prevents you from using the device.
What to do now
- Check whether your offence is on the list above, and whether you had another drink driving offence in the 5 years before the conviction.
- If you need to drive during the disqualification, ask about an extraordinary licence; it will carry the interlock condition.
- Get advice before your court date. Call 1800 577 015 at any hour, or request a $295 consultation with a Western Australian lawyer. The penalties for each reading are in the full table of WA drink driving penalties.
How Go To Court Lawyers can help
Our free line, 1800 577 015, answers at any hour. Jen, our AI legal information assistant, gives general legal information and takes your details; Jen is not a lawyer and does not give advice about your case. A 60-minute consultation with a lawyer who practises in Western Australia is a fixed $295, by phone, video or in person. Go To Court Lawyers does not have a Perth office; the lawyers in our network appear in Western Australian courts in person.
General information only, not legal advice. Updated 22 October 2026. Checked against the Road Traffic (Authorisation to Drive) Act 2008 and Regulations 2014, the Road Traffic Act 1974, the Department of Transport and the Road Safety Commission on 22 October 2026.