Drink Driving

Alcohol limits are set in law. Elimination times are approximate only and vary widely between individuals.

Test type Legal limit – England, Wales & Northern Ireland Legal limit – Scotland Comments Elimination / detection times (other factors apply)
Breath alcohol 35 micrograms per 100 ml of breath 22 micrograms per 100 ml of breath Most common roadside screening test using a breathalyser Alcohol is typically processed at around 1 unit per hour, but this varies greatly. Alcohol can still be present the next morning, even if you feel sober
Blood alcohol 80 milligrams per 100 ml of blood 50 milligrams per 100 ml of blood Used as confirmatory evidence if required Blood alcohol levels rise quickly after drinking and fall slowly. There is no way to speed up elimination
Urine alcohol 107 milligrams per 100 ml of urine 67 milligrams per 100 ml of urine May be used if breath or blood testing is not possible Alcohol may remain detectable for several hours after drinking has stopped

Important things to know

  • It is impossible to calculate how many drinks will put someone over the limit

  • Alcohol affects people differently depending on:

    • weight, age, sex, and metabolism

    • how much and what type of alcohol is consumed

    • whether food has been eaten

    • stress and fatigue levels

  • Even small amounts of alcohol can impair driving ability

  • You can still be over the limit the morning after drinking, even if you feel fine

Alcohol and driving impairment

Alcohol affects many of the skills needed to drive safely:

  • slower reaction times

  • reduced concentration

  • poorer judgement and decision-making

  • impaired vision and coordination

  • increased risk-taking behaviour

Being below the legal limit does not mean it is safe to drive.

Penalties for drink driving

If you are convicted of drink driving, you may face:

  • a minimum 1-year driving ban

  • an unlimited fine

  • up to 6 months in prison

  • a criminal record

If someone is killed due to drink driving, the maximum penalty is life imprisonment.

Your driving licence will show the conviction, insurance costs will rise significantly, and it may affect employment and travel abroad.

Staying safe

There is no reliable way to “drink and stay under the limit”.

The safest advice is simple: if you are driving, do not drink alcohol at all, including the morning after drinking.

Plan ahead by:

  • choosing a designated driver

  • using taxis or public transport

  • choosing alcohol-free drinks

Last Updated on 9 February 2026