Failed Breathalyser? What Happens Next | Complete UK Guide

If you fail a roadside breathalyser test, the police will arrest you and take you to a police station for a more accurate evidential breath test on an approved device. If that second test shows you are over the legal limit of 35 micrograms of alcohol per 100 millilitres of breath, you will be charged with drink driving. The roadside test alone is not enough to convict you. A first-time drink driving conviction typically results in a 12 to 18 month driving ban, a fine of up to 2.5 times your weekly income, and a criminal record.

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Understanding the breathalyser procedure and the steps following a failed breathalyser helps you navigate this stressful situation, make informed decisions, and avoid mistakes that could harm your defence. From roadside arrest to police station evidential testing and eventual court appearances, each stage involves specific procedures, rights, and opportunities for legal challenge that only experienced drink-driving solicitors can fully advise on. Learn more about our comprehensive criminal defence services.

This comprehensive guide explains every step after failing a breathalyser: immediate arrest procedures, police station breath test process, your legal rights, evidential testing requirements, charging decisions, and court proceedings. Whether you’ve failed a roadside preliminary breath test or station evidential test, understanding what comes next helps you protect your interests and prepare for the legal process ahead.

Just failed a breath test? Call our 24/7 emergency line immediately: 0161 660 6050 for urgent legal representation.

Understanding Different Types of Breathalyser Tests

Before examining what happens after a failed breathalyser, it is crucial to understand the difference between preliminary and evidential tests.

Two Types of Breath Tests

Preliminary Breath Test (Roadside)

Purpose: Screening test indicating whether you are likely over the legal limit
Device: Handheld portable breath testing device (roadside breathalyser)
Location: Roadside, at the scene of the stop
Legal Status: Not admissible as evidence in court
Result: Pass or fail only (no specific reading usually given)
Consequences:
- Pass: Free to continue your journey
- Fail: Arrested and taken to the police station for an evidential test
Key Point: A roadside failed breathalyser does not provide evidence used to convict you; it only gives grounds for arrest.

Evidential Breath Test (Police Station)

Purpose: Evidential test providing a precise alcohol reading used in court
Device: Approved evidential breath testing machine (Lion Intoxilyzer, Evidential Breath Analyser)
Location: Police station custody suite
Legal Status: Admissible evidence in court proceedings
Result: Precise reading in micrograms per 100ml of breath
Consequences:
- Under 35 micrograms: Released, no further action
- 35+ micrograms: Charged with drink driving
Key Point: This is the test that matters for prosecution. A roadside failed breathalyser only brings you to the police station.

To understand more about how criminal charges are brought and prosecuted, visit the Crown Prosecution Service website.

Stage 1: Immediate Aftermath – Failed Roadside Breath Test

What Happens Immediately

You’re Arrested
Following a failed roadside breath test, the police officer will:

Formally Arrest You:
“You’re under arrest on suspicion of driving whilst over the prescribed alcohol limit.”
This is a clear statement confirming your arrest.
Caution You:
“You do not have to say anything, but it may harm your defence if you do not mention when questioned something which you later rely on in court. Anything you do say may be given in evidence.”
It is critical that you understand this caution.
Explain Why You’re Arrested:
The officer will state the grounds for your arrest, usually referencing the failed breathalyser.
Note the Time:
The time of arrest is recorded and may be important for establishing the timeline of events later.

What You Should Do

Do:

Remain calm and cooperative
Listen carefully to everything the police say
Note officer details, including collar number and name
Remember the exact time of arrest if possible
Ask for legal representation immediately

Don’t:

Argue or become confrontational
Make any statements about alcohol consumption
Estimate how much you drank
Admit to drinking and driving
Provide any explanations without legal advice

Critical Point: Anything you say from this moment can be used against you. Say nothing about alcohol consumption until you have legal representation.

For more information about your legal rights during arrest, visit Gov.uk’s guide to your rights at the police station.

Your Vehicle

What Happens to Your Car:

You cannot continue driving as you are under arrest
The police may seize your vehicle if no sober driver is available
A friend or family member who is sober may collect it
Otherwise, the vehicle may be recovered to a police pound (fees apply)
Make safe arrangements for vehicle collection later

Vehicle Recovery Costs:

Recovery fee: £150–£250
Daily storage: £15–£30 per day
Release requires proof of ownership and insurance

Search

Personal Search:

The officer may search you for safety reasons
They will check for weapons, contraband, or evidence
Items are logged and placed in custody property

Vehicle Search:

Police may search the vehicle for evidence
They may look for open alcohol containers, drug paraphernalia, or documents

Stage 2: Transport to Police Station

Journey to the Station

What Happens:

You are transported in a police vehicle, usually seated in the rear.
Officers may ask questions, but you should say nothing without legal advice.
The journey typically lasts 10–30 minutes.

Your Rights During Transport:

Right to remain silent
Not obliged to answer questions
Anything you say can be used in evidence
Reasonable treatment is expected

What You Should Do:

Remain calm and cooperative
Do not engage in conversation about drinking
Do not make admissions
Note any threats, inducements, or pressure
Remember you are under arrest and do not attempt to leave

Common Police Questions (Do Not Answer Without Legal Advice):

“How much have you had to drink?”
“When did you last drink?”
“Where were you drinking?”
“Where are you coming from?”

Proper Response:
“I’d like to speak to a solicitor before answering questions.”

Stage 3: Arrival at Police Station – Booking In Process

Custody Sergeant Processing

Upon arrival, the custody sergeant (separate from the arresting officer) will process you following a failed breathalyser:

Rights Explanation
You will be informed of three fundamental rights:

Right to Free Legal Representation:
- Duty solicitor (free, available 24/7)
- Your own solicitor (free under legal aid for police station)
- Critical: always exercise this right
Right to Have Someone Informed:
- Police will notify a friend or family member of your arrest
- They can assist with practical matters such as your vehicle or childcare
Right to Consult Codes of Practice:
- Access to PACE Codes governing police procedures
- Available for consultation

Critical: Request legal representation immediately. Our 24/7 service: [Phone Number]

Medical Assessment
The custody sergeant assesses whether you are:

Fit to be detained
Fit to be interviewed
In need of medical attention
Under the influence of alcohol or drugs (observation)

Medical issues you should mention include:

Respiratory conditions (asthma, COPD)
Panic attacks or anxiety
Medication you take
Recent food or drink
Any other health concerns

Personal Details Recorded
The sergeant records:

Name, address, date of birth
Contact details
Next of kin
Any vulnerabilities

Property Logged
All personal property is recorded and secured:

Wallet, phone, keys
Jewellery, watches
Vehicle documents
Everything itemised on the custody record

Photographs and Fingerprints

Photograph taken
Fingerprints recorded
DNA sample may be taken
Routine procedure for arrests

Risk Assessment
Assessment includes:

Risk of self-harm
Risk of violence
Medical needs
Vulnerabilities

This determines cell placement and observation level.

Typical Booking Time: 15–30 minutes

Our police station representation service attends immediately during this critical period.

Stage 4: The 20-Minute Observation Period

Before an evidential breath test can proceed, a mandatory 20-minute observation period must be completed.

Purpose of Observation Period:
This ensures that any residual mouth alcohol does not contaminate the breath test, preventing falsely elevated readings from:

Recent drinking (alcohol still in the mouth)
Vomiting or regurgitation
Burping, bringing stomach contents to the mouth
Eating food containing alcohol
Using mouthwash or breath fresheners

What Happens During 20 Minutes:

Continuous Observation: An officer or detention officer will watch you constantly and you cannot leave their sight.
Monitoring for contamination events.

You Must Not:

Eat or drink anything
Smoke or vape
Use mouthwash or breath spray
Chew gum
Vomit or regurgitate
Burp (inform the officer immediately if you do)

If Contamination Occurs:
The officer must restart the 20-minute period from the beginning. If you vomit or burp:

Inform the officer immediately
The 20 minutes will restart
This procedure is not intended to delay the test but to protect its accuracy.

Legal Requirement:
Police must observe the full 20-minute period; any shorter observation invalidates the test results.

Defence Opportunity:
If the observation period is incomplete or interrupted, evidential breath test results following a failed breathalyser may be challenged and excluded from evidence.

What You Should Do:

Sit quietly and remain calm
Do not eat, drink, or smoke
Inform the officer if you burp, vomit, or have reflux
Note the start and end times
Remember if the observation period was interrupted
Wait for your solicitor if they have not arrived

Stage 5: Evidential Breath Test Procedure

The evidential breath test at the police station is the reading that matters for your case. If your reading is close to the legal limit, there may be grounds to challenge the charge. Our drink driving solicitors regularly handle cases where the breath reading is borderline, and small procedural errors by the police can make the difference between a conviction and an acquittal.

After the 20-minute observation period, you will provide an evidential breath sample.

The Testing Process:

Legal Rights Reminder
Before testing, the custody sergeant confirms:

You understand you are required to provide a specimen
Failure without reasonable excuse is an offence
You have the right to consult a solicitor before providing a specimen

Wait for Your Solicitor:
You are entitled to legal advice before testing. Do not proceed without speaking to a solicitor. Our 24/7 service ensures immediate attendance.

Test Explanation
The officer will explain:

Two breath samples must be provided
Blow continuously until told to stop
The lower of the two readings will be used
The process takes several minutes

Providing Breath Samples

First Sample: Mouthpiece placed in the machine; take a deep breath and blow continuously. Machine analyses sample; reading displayed.
Second Sample: New mouthpiece; repeat process. Reading displayed.
Lower Reading Used: The lower reading is used for the charging decision, more favourable than the higher reading.

Test Results

Under 35 micrograms: Under legal limit; released with no further action.
35–39 micrograms: Over limit but low reading; special statutory option may apply.
40–50 micrograms: Over limit; statutory option to replace with blood or urine test.
51+ micrograms: Clearly over limit; no option to replace with blood or urine; charged based on breath reading.

Breath Test Printout:
The machine produces a printout showing:

Date and time
Two readings (lower reading used)
Officer and your details
You receive a copy, which is important evidence for your defence.

What If You Cannot Provide a Sample?

Genuine Medical Reasons: Asthma, COPD, panic attacks, physical injuries affecting breathing. Inform the custody sergeant immediately; a medical examination will be arranged and an alternative blood or urine sample offered.
Failure Without Reasonable Excuse: Refusing to provide a sample, not trying properly, or deliberately failing constitutes a separate offence, carrying the same penalties as drink driving. Never refuse without a valid medical reason.

If you refused the breathalyser test rather than failing it, the legal position is different. Refusing to provide a specimen without a reasonable excuse is a separate offence under section 7(6) of the Road Traffic Act 1988, and it carries penalties similar to drink driving. Our motoring offence solicitors can advise you on the specific defence options for refusal cases.

Stage 6: The Statutory Option (40–50 Micrograms)

If your breath reading is between 40–50 micrograms following a failed breathalyser, you have a statutory option to replace the breath sample with a blood or urine test.

What Is the Statutory Option?
A legal right to elect a blood or urine sample instead of relying on the breath reading.

Why Choose This Option?
Potential Advantages:

Blood tests are more accurate than breath tests
Time delay may reduce alcohol level if still rising during breath test
Mouth alcohol or GERD does not affect blood results
Medical conditions have less impact on blood testing

Potential Disadvantages:

Blood testing takes time to analyse, potentially delaying the case by weeks
May still show over the legal limit (80mg per 100ml blood)
Requires a needle procedure
No guarantee of a better result

Decision Process:

You must decide immediately at the station
Solicitor advice is critical, considering timing of last drink, likelihood alcohol is still rising or falling, and any mouth alcohol or GERD factors

Blood or Urine Sample:

Police decide which test, usually blood
Taken by a doctor or registered nurse
Two samples taken: one for police analysis, one for independent testing

No Statutory Option Available:

Readings under 40: under limit, no charge
Readings 51+: clearly over limit, no option
Only available 40-50 microgram range

For more information about how criminal courts work, visit Citizens Advice’s guide to criminal courts.

Stage 7: Police Interview

After providing a breath sample, the police may interview you about the offence.

Interview Purpose:
The police aim to obtain evidence, including:

Admissions about drinking
Details of alcohol consumption
Timing and location of drinking
Reasons for driving
Any explanations or defences

Your Rights in the Interview:

Right to Legal Representation: A solicitor must be present. Do not proceed without legal advice. Our 24/7 service ensures immediate attendance.
Right to Silence: You are not obliged to answer questions and may respond “no comment” to all questions. Silence cannot usually be used against you.

Interview Process:

Recording: Interviews are digitally recorded. The date, time, and people present are stated, and the caution is repeated.
Questions Police May Ask:
- What did you drink and when?
- How much did you consume?
- When did you stop drinking?
- Why were you driving?
- Did you know you were over the limit?

Solicitor Advice:

Your solicitor will usually advise “no comment” to prevent inadvertent admissions. Police already have breath test evidence, and additional admissions only help the prosecution.
Prepared statements may sometimes be read into the record, followed by “no comment” to questions.

What Police Are Looking For:

Admissions of drinking and driving knowingly
Estimates of consumption
Reasons undermining potential defences
Inconsistencies to challenge later

Best Approach: Follow your solicitor’s advice—typically responding “no comment” to protect your position after a failed breathalyser.

Stage 8: Charging Decision and Release

After breath testing and the interview, the custody sergeant will make a charging decision.

If Charged with Drink Driving:

Formal Charge:
The sergeant reads the charge:
“You are charged that on [date] at [location] you drove a motor vehicle on a road, namely [road name], after consuming so much alcohol that the proportion of it in your breath, namely [reading] micrograms of alcohol in 100 millilitres of breath, exceeded the prescribed limit.”
Caution Response:
You are cautioned and asked if you have anything to say.
Correct response: “No comment” or “I’ll address this through my solicitor.” Do not make any statements—anything said can be used against you.
Charge Sheet:
You will be given a written charge sheet detailing:

Full name and address
Offence charged
Date, time, and location
Breath reading
Court date and location
Conditions of bail

Bail Conditions:

Usually released on unconditional bail: free to leave, must attend court, keep police informed of address changes
Occasionally conditional bail: residence requirements, not to drive (rare pre-conviction), sign-in requirements at police station

Court Date:

First appearance usually 3–6 weeks from charge
Often at a London magistrates’ court at 10am
Must attend or a warrant may be issued

Property Return:

Personal property returned
Vehicle arrangements discussed
You cannot drive from the police station if still over the limit

Release Time: Typically 3–6 hours from arrival at the station, including observation, testing, interview, and charging.

The penalty you receive depends on how far over the limit your reading was, whether anyone was injured, and whether you have previous convictions. For a detailed breakdown of the sentencing ranges, our drink driving penalty calculator gives you an estimate based on your specific reading level.

Stage 9: After Release – Immediate Actions

Once released following a failed breathalyser, take immediate steps to protect your case:

Contact a Specialist Solicitor:

If you only had a duty solicitor at the station, contact a specialist drink driving solicitor immediately.
Early instruction improves defence prospects.
Call our 24/7 service: [Phone Number]

Preserve Evidence:

Breath Test Printout: Keep it safe, scan or photograph as a backup. Essential for your defence.
Timeline Documentation: Write a detailed timeline while fresh in memory—what you drank, when, amounts, when you stopped drinking, and your driving route.
Witness Details: Note anyone who can corroborate your timeline, including contact details.

Consider Defence Strategies:
Potential defences may include:

Hip flask (drinking after driving but before test)
Rising alcohol (still absorbing at time of test)
Mouth alcohol contamination
GERD or medical conditions
Procedural errors in testing
Special reasons (laced drinks, emergencies)
Discuss all with a specialist solicitor.

Employment Considerations:

If you drive for work, inform your employer early and explore alternative duties.
Do not resign hastily; many cases are successfully defended.

Financial Preparation:
Potential costs may include:

Legal fees (£1,500–£3,500)
Court fines (£200–£1,000)
Vehicle recovery (£150–£300)
Increased insurance if convicted

Arrange Transport:
You cannot drive while over the limit. Arrange:

Family/friend collection from the station
Taxi or public transport home
Vehicle collection by a sober driver

Learn more about our experienced legal team and firm history.

Common Questions After Failing a Breath Test

Can I Drive After Failing a Breathalyser?
No. Absolutely not.

You are over the legal limit.
Driving while over the limit is a criminal offence.
If stopped again, you could be charged with a separate offence.
Insurance is invalid.
Driving shows no remorse, which may be an aggravating factor at sentencing.
Wait a minimum of 12–24 hours depending on alcohol consumed. Use online calculators cautiously or simply do not drive until the next day.

Will I Definitely Lose My Licence?
Not necessarily. Outcomes depend on:

Whether you can successfully defend the charge
Arguments based on special reasons
Exceptional hardship applications
Whether it is a “drunk in charge” or “driving” offence
Many factors affect the outcome. Expert legal advice is essential after a failed breathalyser.

How Long Until Court Date?

Typically 3–6 weeks from charge to first appearance.
Use this time to:
- Instruct a specialist solicitor
- Gather defence evidence
- Prepare mitigation
- Arrange character references
- Consider rehabilitation courses

Can I Go to Work Tomorrow?

Yes, unless bail conditions prevent it (rare).
You cannot drive if your job requires it.
Inform your employer if necessary and consider alternative transport.
Discuss your situation appropriately with your employer.

Should I Tell My Employer?

Depends on your employment contract, company policies, and professional regulations.
Driving requirements may influence disclosure.
Always discuss with your solicitor before deciding.

What If I Have a Medical Condition?

Conditions potentially affecting breath tests include:
- GERD (acid reflux)
- Diabetes
- Respiratory conditions
- Asthma
Inform the custody sergeant immediately. Medical evidence can be important for your defence. Arrange GP or specialist appointments to document conditions.

What Happens at Court – Overview

First Appearance (3–6 weeks after charge):

Arrive Early: 30 minutes before hearing
Meet Solicitor: Discuss your case and plea
Charges Read: Magistrates read allegations
Plea Entered: Guilty or not guilty
Prosecution Summary: Brief facts outlined
Defence Mitigation (if guilty plea): Solicitor presents your case

Sentencing or Trial Date:

Guilty Plea: Usually sentenced the same day
Not Guilty Plea: Trial date set 6–12 weeks ahead

Likely Outcomes:

If Guilty Plea:

Minimum 12-month driving ban
Fine, typically £200–£600
Criminal conviction
Possible rehabilitation course offer

If Not Guilty Plea:

Trial date set
Continue on bail
Defence evidence prepared
Trial usually lasts 2–3 hours

Special Reasons / Exceptional Hardship:

Additional hearing after conviction
Evidence presented (witnesses, documents)
Court decides whether to reduce or avoid a ban

Our court representation services provide expert advocacy throughout proceedings.

Frequently Asked Questions

What happens if you fail a breathalyser test in the UK?

If you fail a roadside breathalyser test, the police will arrest you on suspicion of drink driving and take you to a police station. At the station, you will be given an evidential breath test on a calibrated machine. If this second reading is above 35 micrograms of alcohol per 100 millilitres of breath, you will be charged. The roadside test is a screening tool only and cannot be used as evidence in court.

Can you refuse a breathalyser test?

You can refuse, but it is a criminal offence to do so without a reasonable excuse. Under section 6 of the Road Traffic Act 1988, refusing a roadside breath test can result in arrest and prosecution. If you refuse the evidential test at the police station without a reasonable excuse, the penalty is the same as for drink driving: a minimum 12-month ban, a fine, and a criminal record.

How accurate are roadside breathalyser tests?

Roadside breathalysers are screening devices, not precision instruments. They give a pass/fail indication rather than an exact reading. This is why the police must take you to a police station for an evidential breath test on an approved device (such as the Intoximeter EC/IR or the Evidenzer) if you fail the roadside test. Only the station reading is admissible as evidence in court.

Can you beat a breathalyser charge?

There are legitimate legal defences to a drink driving charge after failing a breathalyser. These include procedural errors by the police (failure to follow the correct testing protocol), problems with the calibration or maintenance of the testing device, the “hip flask” defence (if you consumed alcohol after driving but before the test), and medical conditions that can affect breath readings. Each case depends on its specific facts.

How long after drinking can you fail a breathalyser?

Alcohol takes time to leave your system. As a rough guide, it takes about 1 hour for your body to process one unit of alcohol, but this varies by weight, metabolism, food intake, and other factors. A large glass of wine (3 units) could keep you over the limit for 3 hours or more. Many people fail morning-after breathalysers because they underestimate how long alcohol stays in their system. There is no reliable way to speed up the process.

Get Immediate Legal Help After Failing a Breath Test

If you’ve just failed a breath test or are currently at a police station, getting immediate specialist legal representation is critical for protecting your rights and building your defence.

Why immediate action matters:

The hours immediately after arrest are critical. Decisions made at the police station affect your entire case. Without expert legal advice you risk:

Making admissions that harm your defence
Missing defence opportunities
Accepting incorrect procedures
Not exercising important rights

Contact our 24/7 emergency service now:

24/7 Emergency Line: 0161 660 6050

Email: Info@scarsdalesolicitors.com

Office Address: Reed House, 3–4 Hunters Lane, Rochdale, Greater Manchester, OL16 1YL

Website: www.scarsdalesolicitors.com Or complete our online contact form for a callback within hours.

What we provide:

Immediate Police Station Attendance: Within 1 hour anywhere in London
Free Police Station Representation: Under legal aid regardless of income
Rights Protection: Ensure police follow correct procedures
Interview Advice: Guidance on whether to answer questions
Defence Strategy: Early identification of defence opportunities

After charge, we provide:

Comprehensive case review
Evidence gathering and investigation
Expert witness instruction if needed
Court representation
Special reasons/exceptional hardship applications
Fixed fee options available

Time-sensitive actions:

Breath test procedures must be documented immediately
Defence evidence needs securing while fresh
Witness statements required while memories are accurate
Medical evidence is arranged promptly
Early preparation maximises success prospects

Don’t navigate this alone. Many clients achieve successful outcomes through expert representation who would have been convicted without specialist help.

Learn more about our police station representation and 24/7 emergency legal services.

Call Now: 0161 660 6050

Protect your rights and your licence with immediate specialist legal representation.