NEW SOUTH WALES

Drink Driving Defences NSW

In shortA NSW drink driving charge is not automatically proved. The prosecution must prove you were driving or attempting to drive, that the test was lawfully obtained, and your reading. A breath analysis within 2 hours is presumed to be your reading at the time of driving unless you prove it was lower, which is where rising BAC evidence can matter.

What police must prove: driving (or attempting to put the vehicle in motion, or supervising a learner), on a road or road-related area, with the prescribed concentration of alcohol (Road Transport Act 2013 s 110).
The 2-hour presumption: a breath analysis or blood sample within 2 hours is taken to show your reading at the time of driving, unless you prove a lower reading (Sch 3 cl 31(3)).
Other defences: testing outside the legal limits (Sch 3 cl 2), honest and reasonable mistake in rare cases, and necessity or duress in genuine emergencies.

New South Wales law · law checked 21 Oct 2026

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What's on this page

Can you defend a drink driving charge in NSW?

Yes. Being charged with a drink driving offence in NSW does not mean you will be found guilty. Drink driving law is technical. The prosecution must prove every element beyond reasonable doubt. Where it cannot, or where key evidence is excluded, the court must find you not guilty. In other cases, a properly prepared defence may lead the prosecution to withdraw or replace a charge.

This guide explains the main defences to prescribed concentration of alcohol (PCA) charges under the Road Transport Act 2013 (NSW). Whether any of them is available depends on the police brief and your own evidence.

What must the police prove?

Most NSW drink driving charges are PCA offences under s 110 of the Road Transport Act 2013. The prosecution normally needs to prove that:

you were driving a motor vehicle, or occupying the driving seat and attempting to put it in motion, or, as a licence holder, supervising a learner driver;
this happened on a road or road-related area in NSW; and
you had the prescribed concentration of alcohol in your breath or blood for the charge: novice range (above zero for novice and some other drivers), special range (0.02 to under 0.05), low range (0.05 to under 0.08), middle range (0.08 to under 0.15) or high range (0.15 or more).

The reading usually comes from a breath analysis or a blood test. Whether that evidence can be used is a separate question: if it was obtained unlawfully or outside the legal limits on testing, it may be excluded.

Main defences to a drink driving charge in NSW

1. You were not driving or attempting to drive

Being in a car is not enough. If you were sitting in a parked car with no attempt to put it in motion, the prosecution may not be able to prove you were driving or attempting to drive. The facts matter: where you were sitting, whether the engine was running, where the keys were and what you were doing when police arrived. This can be decisive where police approach someone who was simply waiting in a car.

2. Testing outside the legal limits or contrary to procedure

Schedule 3 to the Road Transport Act sets out when police can require a breath test, breath analysis or blood sample, and the limits on those powers. For example, police cannot require a breath test or breath analysis more than 2 hours after the event that gave them the power to test, or at your home (Sch 3 cl 2). The instrument must be an approved one operated by an authorised officer.

If police did not comply, your lawyer may challenge the evidence. Evidence obtained improperly or illegally can be excluded under s 138 of the Evidence Act 1995 if the court decides the undesirability of admitting it outweighs its value. If the reading is excluded, the prosecution case on a PCA charge usually fails.

3. The 2-hour presumption, rising BAC and drinking after driving

Under Sch 3 cl 31(3), a breath analysis or blood sample taken within 2 hours of the event is taken to be your reading at the time of driving, unless you prove that your reading at that time was below the relevant limit.

That is where "rising BAC" evidence comes in. Alcohol is absorbed over time, so your blood alcohol concentration can rise for a period after your last drink. A reading at the police station may be higher than your reading when you were driving. With accurate evidence of what you drank and when, a pharmacologist may be able to estimate your reading at the time of driving. The onus is on you to prove it, on the balance of probabilities, and the evidence needs to be precise and credible.

Evidence that you drank alcohol after you stopped driving but before the test can be relevant in the same way.

4. Honest and reasonable mistake of fact

PCA offences do not require proof that you knew your reading. But the common law defence of honest and reasonable mistake of fact can apply in limited situations, for example where your drink was spiked without your knowledge and you reasonably believed you had not consumed alcohol. A belief that you "felt fine" or "thought you were under the limit" after drinking voluntarily is not enough. The defence is fact-specific and needs supporting evidence. For novice range offences there is also a specific statutory defence where the alcohol did not come from drinking an alcoholic beverage or from food or medicine used to consume alcohol (s 110(9)).

5. Necessity or duress

In rare genuine emergencies, for example where you had to drive because of an immediate threat to life or a medical emergency with no reasonable alternative, the defence of necessity or duress may arise. Courts apply these defences strictly. They do not apply just because it was inconvenient not to drive.

What about the licence?

NSW police can suspend your licence immediately at the roadside for some readings, including middle and high range (RTA s 224). That suspension lasts until the charge is decided. If you are convicted, an automatic disqualification applies under s 205 unless the court orders a different period within the limits the Act sets, and a mandatory interlock order applies for some offences.

If you plead guilty, the court can sometimes deal with the matter without recording a conviction under s 10 of the Crimes (Sentencing Procedure) Act 1999. Without a conviction, the automatic disqualification does not apply. A s 10 is not available if you received one for a drink or drug driving offence in the previous 5 years (RTA s 203). See section 10 for drink driving in NSW.

How a lawyer approaches a defended matter

A drink driving charge has real consequences for work, family, insurance and travel. A lawyer will usually:

obtain and analyse the police brief, including the breath analysis certificate and the timing of the tests;
check whether police had the power to require each test and followed the procedure;
consider whether pharmacological evidence is needed for a rising BAC or post-driving drinking argument;
assess whether you were driving or attempting to drive at law;
negotiate with the prosecution where the evidence supports a lesser charge or a withdrawal; and
if there is no defence, prepare you for sentence with references, a traffic offenders program and submissions.

Possible results of a defended matter

Not guilty or dismissed: where evidence is excluded or the prosecution cannot prove an element beyond reasonable doubt.
Withdrawal or a lesser charge: the court can also find you guilty of a lower range if it is not satisfied of the higher one (s 110(6)).
No conviction under s 10: after a plea or a finding of guilt, in suitable cases.

Every case is different. The earlier you get advice, the more options you usually have. For penalties, see drink driving penalties in NSW.

Call 1300 941 900 or make an enquiry about legal representation.

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FAQs: drink driving defences in NSW

Can I be found not guilty of drink driving in NSW?

Yes, if there is reasonable doubt about whether you were driving or attempting to drive, if the reading is excluded, or if you prove that your reading at the time of driving was below the limit.

What is the "rising BAC" defence and does it still work?

It relies on the 2-hour presumption being rebutted: you prove, usually with pharmacological evidence and precise timing, that your reading at the time of driving was below the relevant limit. It can work in the right case, but the onus is on you.

Do police have to test me within a certain time?

Yes. A breath test or breath analysis cannot be required more than 2 hours after the event that gave police the power to test (Sch 3 cl 2). Blood samples have their own limits.

What is a section 10 outcome?

A dismissal or conditional release order without conviction under s 10 of the Crimes (Sentencing Procedure) Act. It avoids the automatic disqualification, but it is not available if you had one for drink or drug driving in the previous 5 years.

Do I need a lawyer for a first offence?

It is not compulsory, but even a first low range offence can lead to disqualification, a fine and a criminal record. Advice helps you decide whether to defend the charge and how to prepare.

Sources and date checked

The law on this page was checked against these primary and official sources on 21 Oct 2026. Penalty unit dollar amounts are as at 21 Oct 2026.

Road Transport Act 2013 (NSW) – ss 110, 203, 205, Sch 3 cll 2, 3, 31 — checked 21 Oct 2026
Crimes (Sentencing Procedure) Act 1999 (NSW) – s 10 — checked 21 Oct 2026
Evidence Act 1995 (NSW) – s 138 — checked 21 Oct 2026
Judicial Commission of NSW – Local Court Bench Book, PCA offences — checked 21 Oct 2026

This page is general information about New South Wales law only. It is not legal advice. Every matter turns on its own facts.

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Court & next listing date: Which court is on your paperwork and when your matter is listed.
Charge or reading (if known): Tell us the charge or reading if you have it — you do not need your full police facts yet.
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