Drink Driving Limit UK: England, Wales, Scotland, NI

The UK's drink drive limit is not one figure for the whole country. England, Wales and Northern Ireland share a blood alcohol limit of 80mg per 100ml, but Scotland has applied a stricter 50mg limit since December 2014, with its own breath and urine limits too.

The Drink Drive Limit by Nation

The limit is measured in three ways: the amount of alcohol in your blood, your breath, or your urine. Whichever measurement the police use, going over any one of these figures for your nation is the offence.

Scotland's lower limit has applied since 5 December 2014, when the Scottish Government used its devolved powers to set a stricter threshold than the rest of the UK. Northern Ireland is also a devolved nation, but its drink drive limit has stayed aligned with England and Wales rather than following Scotland's example, so it is worth checking which limit applies before you drive across the Irish border or between Great Britain and Northern Ireland.

Why You Can't Convert the Limit into "Units" or Drinks

There is no dependable rule of thumb, such as "two pints" or "a large glass of wine", that tells you whether you are under the limit. How much alcohol ends up in your blood, breath or urine after a given drink depends on your body weight, your sex, your metabolism, how much food you have eaten, how quickly you drank, and even the specific drink's strength. Two people who have had exactly the same drinks can produce very different readings, and the same person can vary from one occasion to the next.

Because of that variation, gov.uk and Police Scotland do not publish a "safe" number of units or drinks that guarantees you will stay under the limit. The only way to be certain you are not breaking the law is not to drink any alcohol at all before driving. If you have been drinking the night before, bear in mind that alcohol can still be in your system, and above the limit, the following morning.

Roadside Testing and Refusing a Test

Police can stop a vehicle and require the driver to take a preliminary breath test at the roadside if they suspect the driver has alcohol in their body, has committed a moving traffic offence, or has been involved in a road traffic accident. If that roadside test suggests you are over the limit, or you fail it, you can be arrested and taken to a police station for an evidential breath, blood or urine test, which is the sample used in any prosecution.

Refusing to provide a specimen without a reasonable excuse is itself an offence, separate from and in addition to drink driving, and is generally treated by the courts in a similar way to driving over the limit. There is no legal right to refuse a breath test because you would rather have a blood or urine test instead, or to insist on speaking to a solicitor before providing a roadside sample.

What Happens if You're Over the Limit

Driving or attempting to drive over the relevant limit is a criminal offence with serious consequences, including a driving ban of at least 12 months, up to 6 months in prison and a fine that is unlimited in England and Wales and up to £5,000 in Scotland and Northern Ireland. Being in charge of a vehicle over the limit, without driving it, is a separate offence carrying up to 3 months in prison, a fine of up to £2,500 and 10 penalty points or a discretionary ban. The full penalties, how a second offence within ten years is treated more harshly, and how the drink drive rehabilitation course can reduce a ban are set out on the drink driving ban page.

A conviction for driving or attempting to drive over the limit also carries a DR10 endorsement on your licence (being in charge over the limit is recorded as DR40), which stays on your driving record for 11 years and can significantly increase your insurance costs. For how endorsements and points work more generally, see the penalty points guide.

This article is for general information only and is not legal advice. If you are facing a drink driving investigation or charge, get advice from a solicitor as soon as possible, since the details of your case will affect the outcome. For more on UK motoring law, see the UK Driving Laws hub and the United Kingdom hub, or read about speeding fines and penalty points.

Frequently Asked Questions

What is the drink driving limit in England and Wales?

In England and Wales the limit is 80mg of alcohol per 100ml of blood, 35 micrograms per 100ml of breath, or 107mg per 100ml of urine.

What is the drink driving limit in Scotland?

Scotland's limit is lower than the rest of the UK: 50mg of alcohol per 100ml of blood, 22 micrograms per 100ml of breath, or 67mg per 100ml of urine. It has applied since 5 December 2014.

Does Northern Ireland use the Scottish limit or the England and Wales limit?

Northern Ireland uses the same limit as England and Wales, 80mg per 100ml of blood, not the lower Scottish limit, even though Northern Ireland is also a devolved nation.

How many units of alcohol can I drink and still be under the limit?

There is no reliable answer. How a drink affects your blood, breath or urine alcohol level depends on your weight, sex, metabolism, what you have eaten and how quickly you drank, so the same amount of alcohol can put one person over the limit and leave another under it. The only safe approach is not to drink at all before driving.

Can I refuse a breath test?

Refusing the roadside breath test without a reasonable excuse is an offence carrying a fine of up to £1,000, 4 penalty points and a possible ban. Refusing the evidential breath, blood or urine specimen at the police station after driving is treated like drink driving itself: a minimum 12-month ban, up to 6 months in prison and a heavy fine.

Can I still be over the limit the morning after drinking?

Yes. Alcohol takes time to leave your system, and it is entirely possible to be over the legal limit the following morning, particularly after drinking heavily or late at night.

What happens if I'm convicted of drink driving?

A conviction for driving or attempting to drive over the limit carries a minimum 12-month disqualification, up to six months' imprisonment and a fine that is unlimited in England and Wales and up to £5,000 in Scotland and Northern Ireland, with a DR10 endorsement on your licence. Being in charge of a vehicle over the limit without driving it carries up to three months' imprisonment, a fine of up to £2,500 and 10 penalty points or a discretionary ban, recorded as DR40. See the drink driving ban page for the full penalty structure.