Drink driving is a serious criminal offence in the UK. Even relatively small amounts of alcohol can affect your ability to drive, and there is no reliable way to calculate exactly how much alcohol you can consume before reaching the legal limit.
The law sets strict drink driving limits and laws, but the amount of alcohol that produces a particular reading varies significantly between individuals. Factors including your weight, age, metabolism, the type and amount of alcohol consumed, whether you have eaten recently and even your stress levels can affect your alcohol concentration.
This guide explains the legal alcohol limit, how roadside and evidential testing works, the penalties for drink driving, and what can happen if you are caught drink driving.
What Is The Legal Drink Driving Limit?
The legal alcohol limit differs across the UK.
For drivers in England, Wales and Northern Ireland, the limits are:
| Test | Legal limit |
| Breath | 35 microgrammes per 100ml of breath |
| Blood | 80 milligrammes per 100ml of blood |
| Urine | 107 milligrammes per 100ml of urine |
These are the current limits published by the UK Government.
Scotland has strict alcohol limits:
| Test | Legal limit |
| Breath | 22 microgrammes per 100ml of breath |
| Blood | 50 milligrammes per 100ml of blood |
| Urine | 67 milligrammes per 100ml of urine |
The Scottish limits have been lower than those in England and Wales since December 2014.
How Much Alcohol Can You Drink And Still Drive?
There is no definitive answer to how much alcohol you can drink before driving.
You may hear people refer to one drink, two drinks or a certain number of units as being “safe”, but there is no failsafe way to use this approach.
The amount of alcohol in your blood or breath depends on various factors, including:
- Your weight
- Your age
- Your metabolism
- The type of alcohol consumed
- How much alcohol you drink
- Whether you have eaten recently
- Your stress levels
- How quickly you consumed the alcohol
The government specifically warns that it is impossible to say exactly how many drinks will keep someone below the legal limit.
This means that even small amounts of alcohol can potentially affect different people in different ways.
The safest approach if you intend to drive is not to drink alcohol at all.
Does Eating Make You Safe To Drive?
Eating before or while drinking can affect how quickly alcohol enters your bloodstream, but it does not make driving after drinking safe.
Similarly, drinking coffee, water or soft drinks does not remove alcohol from your body.
There is no reliable method to process alcohol faster – only time allows your body to metabolise alcohol.
This is why “morning after” drink driving can be a particular concern. Someone may stop drinking at night but still have alcohol in their system the following morning.
How Does Alcohol Affect Your Driving?
Alcohol affects driving ability in several ways. It can impair:
- Reaction times
- Concentration
- Coordination
- Judgement
- Vision
- Risk perception
- Decision-making
Even if you do not feel drunk, alcohol can still influence your ability to respond appropriately to hazards.
This is particularly important because someone may believe they are capable of driving after drinking when their actual ability has already been impaired.
Drink driving can contribute to serious road traffic accidents, putting the driver, passengers and other road users at risk.
What Laws Govern Drink Driving In The UK?
Drink driving is governed by several provisions of the Road Traffic Act 1988, which sets out the main offences, police powers and requirements relating to alcohol and driving.
For drivers in England and Wales, one of the key provisions is section 5 of the Road Traffic Act 1988. This makes it an offence to drive, attempt to drive or be in charge of a motor vehicle on a road or other public place after consuming enough alcohol for the proportion of alcohol in the breath, blood or urine to exceed the prescribed limit.
The legislation therefore means that a driver does not necessarily have to appear drunk or obviously impaired – it’s whether the alcohol concentration in their system exceeds the prescribed legal limit.
Section 4 Of The Road Traffic Act 1988
Section 4 creates a separate offence of driving, attempting to drive or being in charge of a motor vehicle while unfit through drink or drugs. This focuses on whether the person’s ability to drive is impaired by alcohol or drugs, rather than simply whether their alcohol concentration is above the prescribed limit.
This distinction is important because a person could potentially face prosecution for being unfit through drink even where the evidence does not establish the standard section 5 excess alcohol offence.
Section 5 And The Drink Drive Limit
Section 5 is the provision most commonly associated with driving over the legal alcohol limit.
Under the legislation, it is an offence to drive or attempt to drive with an alcohol concentration above the prescribed limit. It also covers being in charge of a vehicle while over the limit, although a specific defence can apply where the person can show there was no likelihood of them driving while over the prescribed limit.
This is why simply deciding not to drive after drinking is important. Being in or around a vehicle while over the limit can create separate legal issues depending on the circumstances.
Section 7: Providing A Specimen
The Road Traffic Act 1988 also gives the police powers to require specimens as part of a drink driving investigation.
Depending on the circumstances, a driver may be required to provide a breath, blood or urine specimen. Failure to provide a specimen when lawfully required can itself constitute an offence, unless the person has a legally recognised reasonable excuse.
The circumstances surrounding the request for a specimen, the testing procedure and the evidence obtained can therefore all be important if a drink driving allegation proceeds to court.
Causing Death While Under The Influence Of Drink
More serious offences apply where a driver’s actions result in the death of another person.
Under section 3A of the Road Traffic Act 1988, causing death by careless driving while under the influence of drink or drugs is a separate offence. The maximum penalty for offences committed after 28 June 2022 is life imprisonment.
The law therefore treats drink driving that causes a fatality considerably more seriously than a standard excess alcohol offence.
Why The Road Traffic Act Matters
The Road Traffic Act 1988 provides the legal framework for many of the issues that arise following a drink driving allegation, including:
- Driving over the prescribed alcohol limit
- Being in charge of a vehicle while over the limit
- Driving while unfit through drink
- Police requirements to provide specimens
- Failure to provide a specimen
- Causing death by careless driving while under the influence of drink or drugs
Understanding which offence has been alleged is important because the elements of the offence, available defences and potential penalties can differ.
If you have been arrested or charged with a drink driving offence, specialist legal advice can help you understand which provision of the Road Traffic Act 1988 applies to your circumstances and what this could mean for your driving licence and future.
What Happens At The Police Station?
If you fail a roadside test, you will generally be taken to a police station for an evidential test.
Depending on the circumstances, this may involve:
- An evidential breath test
- A blood sample
- A urine sample
The evidential test is different from the initial roadside screening test and can be used as evidence in court. Government statistics explain that drivers are typically given a preliminary breath test at the roadside before being taken to a police station for an evidential test.
There are specific legal procedures surrounding the provision and analysis of samples, meaning that the circumstances in which the test was administered can be important in some cases.
What Is Blood Alcohol Concentration?
Blood alcohol concentration, often referred to as BAC, describes the amount of alcohol present in the blood.
For drivers in England, Wales and Northern Ireland, the relevant limit is 80 milligrammes of alcohol per 100 millilitres of blood.
A blood result can therefore be highly significant in a drink driving prosecution.
However, blood alcohol levels can change over time, meaning the timing of a sample and the circumstances surrounding the analysis may be relevant to the case.
What Is The Penalty For Drink Driving?
If you are found guilty of being in charge of a vehicle or driving while over the prescribed alcohol limit, the consequences can be significant.
For the standard offence of driving or attempting to drive while over the legal alcohol limit, the penalties can include:
- A minimum 12-month driving ban
- An unlimited fine
- Up to six months in prison
- A criminal record
- An endorsement on your driving licence for 11 years
The actual sentence will depend on the circumstances.
The level of alcohol recorded can be particularly important when determining the appropriate penalty, alongside factors such as previous convictions and whether the offence involved a collision or other aggravating circumstances.
Can You Go To Prison For Drink Driving?
Yes, although imprisonment is not the outcome in every case.
A custodial sentence can be imposed where the circumstances justify it, particularly in more serious cases.
The court will consider the applicable sentencing guidelines, the level of alcohol, the nature of the driving and any aggravating or mitigating circumstances.
For a standard drink driving offence, the maximum custodial penalty is six months.
More serious offences, particularly those involving death, have substantially higher maximum penalties.
What Are Aggravating Factors In Drink Driving Cases?
Aggravating factors can make a drink driving offence more serious and may result in a higher sentence.
Depending on the circumstances, these can include:
- A high level of alcohol
- Previous relevant convictions
- Poor or dangerous driving
- A collision
- Other traffic offences committed at the same time
- Driving while already disqualified
- Carrying passengers
- Particularly dangerous circumstances
- Attempts to evade detection
The court will consider the overall circumstances rather than simply looking at the alcohol reading.
What Are Mitigating Factors?
The court can also consider mitigating factors that may reduce the seriousness of the sentence.
These can include:
- A previously good driving record
- Genuine remorse
- Personal circumstances
- Evidence of rehabilitation
- A low level of offending
- An early guilty plea
- Other circumstances relevant to the individual
The weight given to mitigation depends on the facts of the case.
What Happens If Drink Driving Causes Death?
The consequences are considerably more serious if someone dies as a result of driving under the influence of alcohol or drugs.
The offence of causing death by careless driving whilst under the influence of drink or drugs is governed by section 3A of the Road Traffic Act 1988.
For offences committed after 28 June 2022, the maximum penalty is life imprisonment. The current Sentencing Council guideline provides an offence range of 26 weeks to 18 years’ custody and a minimum five-year driving disqualification, with a compulsory extended re-test.
There is also the separate offence of causing death by dangerous driving, which can carry life imprisonment.
These are among the most serious driving offences and require specialist legal advice.
Can Drink Driving And Drug Driving Be Charged Together?
Yes, depending on the circumstances.
A driver may face allegations relating to both drink driving and drug driving if there is evidence of alcohol and drugs being present or affecting their ability to drive.
The precise offences will depend on the evidence, including alcohol readings, drug test results and the circumstances of the driving.
Where multiple offences are alleged, it is important to obtain specialist advice on how they interact and what penalties could apply.
What If I Was Not Actually Driving?
The law also covers being in charge of a vehicle while over the prescribed alcohol limit.
This can potentially apply even where you were not actually driving at the time.
Whether someone was “in charge” of a vehicle depends on the circumstances. For example, even if you weren’t driving the car, but were sat inside with the keys, this could be classed as being “in charge” of the vehicle, and is still a serious criminal offence.
If you have been accused of being in charge of a vehicle while over the limit, rather than actually driving, specialist legal advice should be sought because the legal issues can be different.
Can You Be Charged With Careless Driving As Well?
If alcohol has affected the standard of your driving, you could face allegations of careless driving or more serious driving offences depending on the circumstances.
Where a collision has occurred, the prosecution may consider the nature of the driving, the level of alcohol and whether anyone was injured or killed.
A drink driving allegation therefore does not necessarily exist in isolation from other road traffic offences.
What If I Am A High-Risk Offender?
Some people convicted of drink driving are classified as high risk offenders.
This can apply, for example, if you:
- Have been convicted of two drink driving offences within 10 years
- Were driving with a particularly high alcohol reading
- Refused to provide a sample in certain circumstances
High-risk offenders may need to undergo a medical examination with a DVLA appointed doctor before they can regain their licence.
The medical examination can involve questions about your medical history and alcohol use, a physical examination and blood testing.
Can You Reduce A Drink Driving Ban?
If you are disqualified from driving for 12 months or more, you may be eligible to take a drink-drive rehabilitation course.
Successfully completing an approved course can reduce the length of your driving ban in qualifying circumstances.
Eligibility depends on the circumstances of the conviction and the length of the disqualification.
Does A Drink Driving Conviction Affect Insurance?
A drink driving conviction can have a significant impact on your finances.
You may face increased car insurance costs, particularly because insurers can consider driving convictions when calculating premiums.
There can also be wider consequences, including difficulties with employment, travel and maintaining your independence.
The government’s road safety campaign highlights increased insurance costs and potential employment consequences among the wider impacts of a drink driving conviction.
What Should You Do If You Are Caught Drink Driving?
If you have been caught drink driving, it is important to take the allegation seriously.
You should:
- Keep copies of any paperwork you receive.
- Make a note of the circumstances surrounding the stop and testing.
- Record what happened at the roadside and police station while your memory is fresh.
- Keep details of any medical issues or medication that may be relevant.
- Avoid making assumptions about the likely outcome based solely on your alcohol reading.
- Obtain specialist legal advice as soon as possible.
There may be important questions about the testing procedure, the evidence, the circumstances of the stop or whether the prosecution has established the necessary elements of the offence.
Expert Drink Driving Solicitors At McArthur Solicitors
A drink driving allegation can have consequences that extend far beyond a driving ban. A conviction can affect your finances, employment, insurance and personal circumstances, while more serious cases can result in imprisonment.
At McArthur Solicitors, our criminal defence team has experience dealing with driving offences, including drink driving allegations and cases involving serious road traffic incidents. We can assess the circumstances of your arrest, the evidence surrounding the breath or blood test and any other issues that may affect your case.
Whether you have recently failed a roadside breath test, have been arrested and taken to a police station, or are facing court proceedings following a serious collision, obtaining specialist advice early can help you understand your position and the options available.
If you have been charged with drink driving or another road traffic offence, contact McArthur Solicitors today for expert criminal defence advice and representation.
