Impaired driving laws in Ontario and across Canada have changed significantly over the past decade. One of the most impactful developments was the introduction of mandatory alcohol screening, which expanded police powers to demand roadside breath samples from drivers even in the absence of any suspicion of impairment.
As a result, many drivers now face a critical, often misunderstood question during routine traffic stops: Can you legally refuse a roadside breath test in Ontario, and what happens if you do?
While the short answer is that refusal is physically possible, the legal consequences of refusing a roadside breath test are severe and, in many cases, mirror or exceed those of a standard impaired driving conviction.
This article provides a comprehensive legal analysis of roadside breath testing in Ontario, grounded in the Criminal Code of Canada, the Canadian Charter of Rights and Freedoms, and Ontario’s Highway Traffic Act. It explains what police are legally allowed to demand, what drivers are legally required to do, and how refusal cases are defended in court.
Roadside breath testing in Canada is governed by Part VIII.1 of the Criminal Code, specifically sections 320.27 and 320.15 .
Prior to 2018, police were required to have reasonable suspicion that a driver had alcohol in their body before demanding a breath sample. This changed with amendments introduced through Bill C-46.
Under section 320.27(2) of the Criminal Code , a peace officer may now demand a breath sample from any lawfully stopped driver, provided the officer has an approved screening device in their possession.
“If a peace officer has in their possession an approved screening device, the peace officer may, in the lawful exercise of their powers, require the person operating a motor vehicle to immediately provide samples of breath…”
This provision forms the legal foundation for mandatory roadside screening programs used by the Ontario Provincial Police and municipal police services across Ontario.
From a purely physical standpoint, a driver can refuse to comply with a police demand. Legally, however, refusal is a criminal offence.
Under section 320.15(1) of the Criminal Code , it is an offence to:
Refusal triggers immediate arrest and criminal charges.
“Refusal cases are prosecuted just as aggressively as impaired driving cases — and often with fewer evidentiary hurdles for the Crown,”
— Robbie Tsang, Criminal Defence Lawyer & Managing Partner
Refusing a roadside breath test carries the same criminal penalties as impaired driving, as set out in section 320.19 of the Criminal Code .
| Offence | Penalty |
|---|---|
| First offence | Minimum $2,000 fine |
| Second offence | Mandatory jail |
| Subsequent offences | Increased jail time |
| Indictable prosecution | Up to 10 years imprisonment |
| Summary conviction | Up to 2 years less a day |
A conviction also results in a permanent criminal record, unless later addressed through a discharge or record suspension.
The right to counsel under section 10(b) of the Charter arises only upon arrest or detention. Courts have consistently ruled that roadside breath demands must be complied with immediately, and that delaying to consult a lawyer defeats the purpose of roadside screening.
Drivers may exercise the right to counsel only after arrest, not before providing a roadside sample.
In addition to criminal charges, refusal triggers automatic administrative penalties under Ontario law.
If convicted, drivers face:
These penalties apply regardless of whether the driver was actually impaired.
Drivers are legally required to:
Failure to do so may be interpreted as a refusal.
Police officers must:
Police cannot use force to compel a breath sample.
“Many refusal cases hinge not on what the driver did, but on whether the officer strictly complied with the law,”
— Heather Spence, Criminal Defence Lawyer & Partner
Refusal can occur in two primary ways:
In the second scenario, police must demonstrate that the driver failed to exhale properly, often indicated by the device failing to register airflow.
Defending refusal charges is challenging but not impossible. Successful defences typically fall into two categories.
Examples include:
Courts have dismissed charges where officers attempted to call for a device later, rather than having one in their possession at the time of the demand.
A refusal may be excused if the driver was genuinely unable to provide a sample due to:
These defences require medical evidence and are assessed strictly.
From a legal defence perspective, the answer is almost always no.
Refusal charges:
Most experienced DUI lawyers advise compliance, followed by immediate legal counsel if charges arise.
Refusing a roadside breath test exposes drivers to some of the harshest consequences in Canadian traffic law. Early legal advice can make a critical difference in:
“The moment a refusal occurs, the case becomes highly technical. Early defence strategy matters enormously,”
— Jeff Mass, Criminal Defence Lawyer
The Greater Toronto Area criminal defence lawyers at Mass Tsang have decades of experience defending impaired driving and refusal cases. Their team is known for meticulous analysis of police conduct and aggressive defence of Charter rights.
If you are facing impaired driving or refusal charges, do not delay seeking legal advice.
Contact Mass Tsang today for a confidential consultation.
You can physically refuse, but legally, a refusal is a criminal offence under the Criminal Code. Refusing a lawful demand can result in arrest and impaired driving–equivalent charges.
Refusal may lead to immediate arrest, criminal charges, a minimum $2,000 fine, a criminal record upon conviction, and licence suspension and vehicle impoundment under Ontario law.
No. Under mandatory alcohol screening laws, police may demand a breath sample from any lawfully stopped driver if they have an approved screening device.
No. The right to consult a lawyer arises only after arrest or detention, not before complying with a roadside breath test demand.
Yes. Criminal penalties for refusal are the same as those for impaired driving, including fines, possible jail time, and a criminal record.
Defences may exist if police failed to follow proper procedures or if the driver had a genuine medical or cognitive condition preventing them from providing a breath sample.
