Impaired Driving Laws in Canada: The Federal Rules

Impaired driving in Canada is defined and punished under the federal Criminal Code, so the core offence and its minimum penalties are the same whether you are pulled over in Halifax, Winnipeg, or Kelowna.

Impaired Driving Is a Federal Offence, Not a Provincial One

Unlike speeding or parking rules, impaired driving is set out entirely in the federal Criminal Code, in Part VIII.1 (sections 320.11 to 320.36). Parliament, not the provincial legislatures, decides what counts as impaired driving and what the minimum sentence is.

That federal framework applies uniformly from coast to coast. What differs by province is what happens to your driver's licence administratively, on top of the criminal charge, which is covered later in this article and in more detail on our DUI penalties in Canada page.

Three Ways to Be Charged

Criminal Code section 320.14 creates three distinct routes to an impaired driving charge, and police only need to prove one of them.

Impairment by ability. Section 320.14(1)(a) makes it an offence to operate a vehicle while your ability to do so is impaired "to any degree" by alcohol, a drug, or a combination of the two. This is proven with evidence such as erratic driving, poor coordination on field sobriety tests, or an officer's observations, regardless of the exact chemical reading.

Blood alcohol concentration ("over 80"). Section 320.14(1)(b) makes it a separate offence to have 80 mg or more of alcohol per 100 mL of blood within two hours of driving. This is a strict, numbers-based offence. It does not matter whether you seemed impaired; the reading alone is enough.

Drug concentration limits. Section 320.14(1)(c) and (d) set blood drug concentration limits by regulation, most notably for THC. A driver can also be charged under section 320.14(4) for a lower THC reading that falls short of the higher threshold but still exceeds the baseline set by regulation.

Mandatory Alcohol Screening: No Suspicion Required

Since December 18, 2018, Criminal Code section 320.27(2) has allowed a police officer who has an approved screening device with them to demand a roadside breath sample from any driver they have lawfully stopped, such as at a checkstop, without needing any reason to suspect that driver has consumed alcohol. This is known as mandatory alcohol screening, and it is a significant departure from the older rule, still found in section 320.27(1), which requires "reasonable grounds to suspect" alcohol or a drug is present in the driver's body before a demand can be made.

Mandatory alcohol screening has been challenged in court as an unreasonable search and an arbitrary detention under the Charter of Rights and Freedoms. Several provincial courts, and at least one provincial Court of Appeal, have found that it does technically limit Charter rights but ruled that the limit is justified as reasonable in a free and democratic society. The Supreme Court of Canada has so far declined to hear a further appeal, leaving those rulings in place across the country.

Federal Penalties: Fines, Jail, and Driving Prohibitions

Section 320.19 sets out mandatory minimum penalties that climb quickly with each subsequent offence and with a higher blood alcohol reading.

On top of a fine or jail time, section 320.24 requires the court to impose a mandatory driving prohibition: at least one year (up to three) for a first offence, at least two years (up to ten) for a second, and at least three years for a third or subsequent offence, each running in addition to any time actually served in custody. Causing bodily harm or death while impaired is punished far more severely under sections 320.14(2) and (3).

Provincial Licence Suspensions Stack on Top

The federal charge is only half the story. Every province also has its own administrative licence suspension scheme, run separately from the criminal court process, that can take your licence away at the roadside the same day you are stopped.

These administrative suspensions apply regardless of the eventual outcome of the criminal case, and they run independently of it. A driver can be back on the road once a provincial suspension ends even while criminal charges are still pending, or conversely can lose driving privileges for months through the administrative process alone if charges are later withdrawn. Each province's transportation authority, not the criminal court, controls this side of the process.

Cannabis and Drug-Impaired Driving

Impairment by drugs, including cannabis, is prosecuted the same way as alcohol impairment under section 320.14(1)(a): proof that your ability to drive was actually affected. Separately, federal regulations set specific blood drug concentration (BDC) limits.

For THC, a reading of 2 to 5 nanograms per millilitre of blood is a summary conviction offence, while 5 nanograms or more is a more serious hybrid offence that can proceed by indictment. A combination of THC at 2.5 nanograms or more together with alcohol at 50 mg or more per 100 mL of blood is also a hybrid offence, reflecting the compounding effect of mixing the two. Provinces including British Columbia and Ontario publish their own driver guidance on cannabis and driving, but the underlying offence and its BDC limits come from the federal regulations, not provincial law.

Impaired vs. "Over 80": Why the Distinction Matters

These are legally two different paths to the same underlying offence category, and understanding the difference matters if you are trying to follow a news story or a court decision. A driver can be convicted of "impaired driving" from officer observations and field sobriety evidence alone, even with no breath or blood sample at all, such as when a driver refuses testing or none was administered. A driver can also be convicted purely on an "over 80" reading even if their driving looked completely normal to onlookers. Crown prosecutors will often charge both routes together and let the evidence determine which one sticks. For a broader look at how impaired driving compares to other serious driving offences, see our page on careless driving vs. dangerous driving.

What Happens After You Are Charged

Once charged, a driver typically faces the immediate provincial administrative suspension described above within hours, followed by a separate criminal court process that can take months. A conviction adds the mandatory federal fine or jail term, the driving prohibition, and in most provinces a further licence reinstatement process that can include an ignition interlock condition, a remedial education or treatment program, and a reinstatement fee before driving privileges are fully restored. For the specific penalty tiers and reinstatement steps, see DUI penalties in Canada. For a full picture of how the rest of Canada's driving and licensing framework works, start at our Canada driving laws hub.

Disclaimer: This article provides general legal information about Canadian impaired driving law and is not a substitute for advice from a licensed lawyer in your province.