Drink Driving Limits in Ireland — The Numbers That Matter
There isn't one limit — there are two, and which one applies to you depends on your licence and your vehicle. Here are the exact blood alcohol limits, the penalties for crossing them, and why "I felt fine" is no defence the morning after.
Ireland Has Two Drink Driving Limits
The general limit, and a much lower one.
Who the 20mg Limit Applies To
It's a much wider group than people realise.
The lower 20mg limit covers
- Learner permit holders
- Novice drivers — anyone in the first 2 years after passing their test
- Drivers of buses, lorries and work vehicles
- Drivers towing a trailer
- Taxi and PSV (public service vehicle) drivers
Why the lower limit exists
- New drivers have the least crash experience and the highest risk
- Professional drivers carry passengers or heavy loads — the consequences of an error are far greater
- Research consistently shows impairment begins well below the old 80mg limit
- The lower limit removes the guesswork — for these drivers, don't drink and drive at all
Penalties & Disqualification
Every drink driving offence carries at least a disqualification.
| Driver / level (blood alcohol) | Typical outcome | Disqualification |
|---|---|---|
| Fully licensed, 50–80mg (fixed penalty, first offence) | €200 fine | 3-month disqualification |
| Learner / novice / professional, 20–80mg (fixed penalty) | €200 fine | 3-month disqualification |
| Fully licensed, 80–100mg (fixed penalty, if eligible) | €400 fine | 6-month disqualification |
| Higher readings, repeat offences, or refusing a sample | Court — fine up to €5,000 and/or up to 6 months in prison | 1 year or more, set by the court |
How You're Tested
Mandatory checkpoints and roadside breath tests.
At the roadside
- Gardaí operate Mandatory Alcohol Testing (MAT) checkpoints — you can be required to provide a breath sample without any suspicion of an offence
- A roadside breathalyser gives a preliminary reading
- If you may be over the limit, you're brought to a Garda station for an evidential test
The evidential test
- An evidential breath test, or a blood or urine sample, provides the figure used in court
- The result is measured against the limit that applies to you — 50mg or 20mg
- Refusing this test is an offence in its own right
The Morning-After Trap
One of the most common ways ordinary people lose their licence.
Why "Just One or Two" Is a Myth
Impairment starts long before you feel drunk.
Alcohol affects driving in three ways before you ever feel intoxicated: it slows your reaction time, it narrows your judgement of risk (you take chances you'd normally avoid), and it impairs your ability to track several things at once — exactly the skill driving demands. Crucially, it does all this while increasing your confidence, so the impaired driver genuinely believes they're fine.
What people get wrong
- "I'm a big person, it doesn't affect me" — size helps a little, it doesn't make you immune
- "I drove fine" — you got lucky; impairment is invisible until it isn't
- "I had food, so I'm grand" — food slows absorption, it doesn't remove the alcohol
- "It was hours ago" — only if it was enough hours; do the maths and add a margin
The simple rule that never fails
- If you're driving, don't drink — at all
- If you've been drinking, don't drive — not that night, and maybe not the next morning
- Plan the journey home before the first drink
- For learner, novice and professional drivers, the limit is effectively zero — treat it that way
Build the habits that protect your licence
Our coaching focuses on the decisions good drivers make automatically — including the ones that keep you well clear of the limit. Drive safer, drive longer.
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Official Sources & References
- 📋 Citizens Information — Drink driving offences in Ireland
- 📋 RSA — Drink driving
- 📋 An Garda Síochána — Roads Policing
- 📘 Road Traffic Act 2010 (as amended)