Drink Driving UK Limit: What You Need to Know About Legal Limits, Units & Penalties

The drink drive limit in the UK is not one number but three, and it is not the same across the whole country. This guide sets out what the law actually prescribes, what happens if you are caught, and the parts of the system that catch people out — refusing a sample, the ban you cannot shorten, and the medical you have to pass before you get your licence back.

What is the drink drive limit in the UK?

The limit is set by section 11 of the Road Traffic Act 1988, and it is expressed three ways — in breath, in blood and in urine. All three describe the same threshold; which one applies depends on the specimen the police take.[7] In England, Wales and Northern Ireland the limit is 35 microgrammes of alcohol per 100 ml of breath, 80 mg per 100 ml of blood, or 107 mg per 100 ml of urine. Scotland is lower on all three.

Region	Breath (mcg/100ml)	Blood (mg/100ml)	Urine (mg/100ml)
England, Wales, Northern Ireland	35 mcg	80 mg	107 mg
Scotland	22 mcg	50 mg	67 mg

The breath figure is the one that matters in practice, because a roadside screening device and the evidential machine at the station both read breath. Most reporting quotes the blood limit — 80 mg, or 50 mg in Scotland — but nobody takes blood at the roadside. If you have ever wondered which number the machine is comparing you against, it is 35, or 22 north of the border.[1][7]

At 80 mg per 100 ml, England, Wales and Northern Ireland have one of the highest drink drive limits in Europe. Most of the continent sits at 50 mg, and Scotland joined them.

Why is the limit lower in Scotland?

Because Scotland legislated separately. Drink driving limits are devolved, and Scotland reduced its prescribed limit to 50 mg per 100 ml of blood — 22 microgrammes of breath — bringing it into line with most of Europe while England, Wales and Northern Ireland stayed at 80 mg.[4]

The practical consequence is that the same drink can be legal on one side of the border and an offence on the other. A driver at 30 mg is comfortably under the limit in Carlisle and comfortably under it in Gretna too — but a driver at 60 mg is legal in Carlisle and committing an offence in Gretna. Most of the consequences are the same on both sides of the border — the same minimum ban, the same six-month maximum sentence — but the fine is not: England and Wales removed their £5,000 ceiling in 2015 and Scotland kept it.[14]

How many units can you drink before you reach the limit?

There is no number of units that is reliably safe, and this is the single most misunderstood part of the law. The limit measures alcohol in your body, not drinks consumed, so the same pint puts two people at different readings depending on their body composition, sex, what they have eaten and how long ago they drank.

A UK unit is 10 ml (8 g) of pure alcohol.[2]

Drink	Amount	Strength	Units
Beer (pint)	568 ml	5% ABV	~2.8
Wine (large glass)	175 ml	13% ABV	~2.3
Spirits (single)	25 ml	40% ABV	1

Notice that a single pint of ordinary lager is already nearly three units. The old pub arithmetic of "two pints is fine" was built on weaker beer and smaller glasses than most bars now pour. Strength matters as much as volume: a 6% craft pint is over three units on its own.

The only amount of alcohol that reliably keeps you under the limit is none.

What are the penalties for drink driving in the UK?

Driving or attempting to drive over the prescribed limit is an offence under section 5 of the Road Traffic Act 1988.[6] The penalties are more severe than most drivers assume, and one figure in particular is widely quoted wrong. In England and Wales the fine is unlimited. The old £5,000 maximum was the level 5 ceiling on magistrates' court fines, and that ceiling was removed by section 85 of the Legal Aid, Sentencing and Punishment of Offenders Act 2012, which made offences previously capped at £5,000 punishable on summary conviction by a fine of any amount.[9]

That removal was expressly limited to England and Wales, and this is where most guides go wrong in the opposite direction. Scotland still caps the fine at £5,000, because the Scottish standard scale is set by section 225 of the Criminal Procedure (Scotland) Act 1995 and level 5 there remains £5,000.[14]

Offence	Prison	Fine	Disqualification
Driving or attempting to drive over the limit	Up to 6 months	Unlimited	At least 1 year
Being in charge of a vehicle over the limit	Up to 3 months	Up to £2,500	Possible ban
Refusing to provide a specimen	Up to 6 months	Unlimited	At least 1 year
Causing death by careless driving when under the influence	Up to life	Unlimited	At least 5 years

Those fines are the England and Wales position. In Scotland the summary maximum is £5,000 — that applies to driving over the limit and to refusing a specimen. Being in charge is £2,500 in both, because level 4 is £2,500 on either scale. Causing death is tried on indictment, where the fine is unlimited either way.[14]

Two of those rows deserve emphasis. Being "in charge" is an offence even if you never drive — sleeping in the driver's seat with the keys can be enough. And the maximum for causing death by careless driving when under the influence is life imprisonment — a conviction also brings a minimum five-year ban and an extended driving test before the licence comes back.[1][8]

A second conviction within ten years raises the minimum disqualification from one year to three. Beyond the sentence itself, a drink driving conviction is a criminal record, stays on your driving licence for 11 years, and typically raises insurance premiums sharply for years afterwards.[1]

What happens if you refuse to give a breath sample?

Refusing is an offence in its own right, and it is punished as heavily as being over the limit: up to six months in prison, an unlimited fine and a minimum one-year ban.[1][12] Refusing without a reasonable excuse is not a way of avoiding the evidence — it substitutes one conviction for another, and the sentence does not go down.

It also does something worse. Refusing a sample puts you straight into the high risk offender category regardless of what your reading would have been, which means a medical examination stands between you and your licence at the end of the ban.[11]

Can you ask for a blood test instead of the breath reading?

No — not any more, and this is a genuinely outdated belief. Until 2015 a driver whose lower breath reading did not exceed 50 microgrammes could claim the "statutory option" and have it replaced with blood or urine. That right was repealed by the Deregulation Act 2015, with effect from 10 April 2015.[13]

The evidential breath reading now stands on its own. Blood and urine specimens are still taken in defined circumstances — for example where the breath machine is unavailable, or a medical reason prevents its use — but the choice is no longer the driver's to make.

What is a high risk offender?

A high risk offender is a driver the DVLA will not simply hand a licence back to at the end of a ban. You fall into the category if you were convicted of two drink driving offences within ten years, or were driving with a reading of at least 87.5 microgrammes of breath, 200 mg of blood or 267.5 mg of urine, or refused to give the police a sample, or refused to allow a blood sample already taken to be tested.[11]

That breath figure is two and a half times the limit. Reaching it is not exotic — it is a heavy evening rather than a catastrophic one, which is why so many people are surprised to find themselves in the scheme. If you qualify, you receive a D27PH renewal form 90 days before the disqualification ends, and you must pass a medical with a DVLA-appointed doctor before the licence is returned.

Can a drink driving ban be reduced?

Sometimes, by up to a quarter. Where a court disqualifies you for 12 months or more, it may offer a place on a drink-drive rehabilitation course (DDRS). Completing it reduces the ban by a period the court specifies, which under section 34A of the Road Traffic Offenders Act 1988 must be at least three months and no more than a quarter of the original period — so a 12-month ban becomes nine months.[10]

Two caveats. The court may offer the course; it is not an entitlement. And you normally pay for it yourself. Bans of under 12 months carry no reduction at all.[1]

Does the UK have a lower limit for new or professional drivers?

No. Unusually for Europe, the UK applies one prescribed limit to every driver — learner, newly qualified, taxi, HGV or coach. Section 11 sets a single threshold and does not create a reduced tier for novice or professional drivers.[7]

That is worth stating clearly, because the opposite is true across most of the continent: Germany, France, Spain, Italy and many others impose a zero or near-zero limit on drivers in their first years, or on those driving for a living. A British driver used to the domestic rule can be legal at home and over the limit on the same reading abroad.

What does exist is separate: newly qualified drivers who accumulate six penalty points within two years of passing have their licence revoked and must retake the test. And employers, insurers and licensing authorities routinely impose their own zero-alcohol conditions that are stricter than the criminal law.

Can you still be over the limit the morning after?

Yes, and this is where a large share of drink driving convictions actually come from. Your body clears alcohol at a roughly fixed rate that you cannot speed up. Coffee, a cold shower, a big breakfast, exercise and sleep all make you feel more alert without lowering the alcohol in your blood by a single milligramme — they change how awake you are, not how much alcohol is in you.

A heavy night that ends after midnight can easily leave a driver over the limit at eight the next morning. If you finished drinking late, the safe assumption is that the morning is not automatically clear.

Should you use a drink driving limit calculator?

A calculator is useful for understanding how alcohol behaves in your body — how long a given quantity takes to clear, and how much a single strong pint contributes. It is not a clearance certificate. Any estimate is built on averages, and it cannot know your metabolism, your last meal, or what the evidential machine will read.

Our UK BAC calculator reports an estimated blood alcohol level and how long it is likely to take to reach zero. Treat it as information about your evening, never as permission to drive.[3][5]

Safer alternatives

• A designated driver — agreed before the first round, not after the third.
• Taxis and ride-hailing — cheaper than an unlimited fine and a year off the road.
• Public transport, or staying over.
• Alcohol-free alternatives, which have improved enormously and are now standard behind most bars.

The bottom line

The UK limit is 35 microgrammes of breath / 80 mg of blood in England, Wales and Northern Ireland, and 22 / 50 in Scotland. But the limit is the least useful number in this article, because you cannot measure yourself against it at the bar. What you can rely on is the shape of the consequences: an unlimited fine, a minimum one-year ban, a criminal record, and a medical examination before you drive again if your reading was high.

If you are asking whether you are under the limit, you already have your answer — don't drive. 🛑