Driving Under the Influence (DUI) is a serious criminal offence in every Australian state and territory. Unlike PCA offences, which are based on a measurable blood alcohol concentration (BAC), a DUI charge relates to a driver being intoxicated by alcohol or drugs to the extent they are incapable of controlling a vehicle safely.
Police do not need a BAC reading to charge someone with DUI. The charge is usually based on observations of impairment, such as erratic driving, slurred speech, unsteady movement, or failed roadside sobriety tests. DUI charges carry severe penalties including imprisonment, licence disqualification, and criminal conviction.
You may be charged with DUI if police believe you are:
Heavily intoxicated by alcohol (even without a BAC reading)
Under the influence of illicit or prescription drugs
Incapable of controlling a vehicle safely due to substance use
Found slumped or impaired behind the wheel
Refusing or unable to provide a breath, urine, or blood sample
DUI charges can apply even if you were not driving but were in control of the vehicle (e.g. in the driver’s seat with the engine running).
DUI charges are usually laid when:
Police observe dangerous or erratic driving
There’s a vehicle collision or serious incident
A driver fails or refuses a roadside test
The driver shows clear signs of impairment
A person is suspected of drug driving but no test is immediately available
Police rely on observations, witness reports, bodycam footage, and medical or toxicology reports to support a DUI charge.
PCA (Prescribed Concentration of Alcohol) is based on a specific BAC reading
DUI is based on observable impairment, regardless of the reading
DUI is more commonly used in drug-related cases, or when no reading is available
DUI carries heavier maximum penalties and is seen as more serious in some states
Defences to DUI charges may include:
No actual driving – you were not in control of the vehicle
Medical condition caused the symptoms mistaken for intoxication
Involuntary intoxication – unknowingly consumed a substance
Lack of evidence to prove impairment beyond reasonable doubt
Improper police procedure – failure to warn or test correctly
Because DUI is a subjective charge based on observations, legal representation is essential to challenge the police case.
New South Wales (NSW)
Under the Road Transport Act 2013 (NSW), a DUI offence can lead to up to 18 months’ imprisonment, a minimum 12-month licence disqualification, and a fine of up to $3,300 for a first offence. Penalties increase significantly for second offences or if someone was injured.
Victoria (VIC)
Under the Road Safety Act 1986 (VIC), DUI is considered a serious offence with a maximum penalty of 18 months’ imprisonment, large fines, mandatory interlock orders, and automatic licence disqualification.
Queensland (QLD)
Under the Transport Operations (Road Use Management) Act 1995, a DUI conviction can result in up to 9 months’ imprisonment, loss of licence for at least 6 months, and substantial fines. Penalties increase for repeat offences or high-level impairment.
Western Australia (WA)
Under the Road Traffic Act 1974 (WA), DUI offences carry up to 18 months’ imprisonment, a minimum fine of $900, and licence disqualification for at least 10 months. Refusing to provide a sample can lead to similar or worse penalties.
South Australia (SA)
Under the Road Traffic Act 1961 (SA), DUI is punishable by up to 12 months’ imprisonment, $1,600+ in fines, and a minimum 12-month disqualification. Aggravating factors (accidents, children in car) can lead to harsher penalties.
Australian Capital Territory (ACT)
Under the Road Transport (Alcohol and Drugs) Act 1977 (ACT), DUI can result in up to 1 year’s imprisonment, fine of over $1,500, and automatic disqualification of at least 6 months.
This page offers general information only and is not a substitute for legal advice. Traffic laws and penalties vary by state. If you’re charged or under investigation, seek help from a criminal lawyer or legal aid service in your jurisdiction.
While we don’t provide legal advice—as every case is unique and only a qualified lawyer is permitted to do so—we’ll do our best to guide you with relevant general information. If we’re unable to assist, we can refer your query to a licensed criminal lawyer.
