BAC Limits in Ireland

BAC limits by country: USA  ·  Canada  ·  Australia  ·  United Kingdom  ·  Ireland  ·  India

• General limit 0.05% (50 mg)
• Learner, novice & unlicensed 0.02% (20 mg)
• Trucks, buses, heavy trailers & taxis at work 0.02% (20 mg)

Understanding the Table

• Legal Limit — Irish law states the limit in milligrams of alcohol per 100 millilitres of blood: 50 mg equals 0.05% BAC, 20 mg equals 0.02%. The offence is to exceed the limit, and it is judged on your level within 3 hours after driving (Road Traffic Act 2010, section 4).
• Breath and Urine — The same limits as the law writes them for the other two tests: 22 µg / 100 ml of breath or 67 mg / 100 ml of urine in general, 9 µg / 100 ml and 27 mg / 100 ml for the lower limit.
• The Lower Limit — Section 3 of the Act lists the “specified persons” who drive on 20 mg: learner permit holders, drivers within 2 years of their first full licence, anyone without a licence for the vehicle they are driving — and drivers of certain vehicles, whatever their experience.

Who Drives on Which Limit

Data based on statutes as of October 2026 (last legal-data review: 7 October 2026). BE, CE, C1E, DE and D1E were called EB, EC, EC1, ED and ED1 in the Act; the new names apply since 31 July 2023 (Road Traffic and Roads Act 2023, section 3).

Key Things to Know

The Professional Limit Follows the Vehicle, Not the Driver

The 20 mg limit for trucks (C, C1 and their trailer categories), buses (D, D1 and theirs), cars towing a heavy trailer (BE) and work vehicles (W) applies while you are driving such a vehicle. A truck driver going home in their own car is on the general 50 mg limit. The same goes for taxi, hackney and limousine drivers: 20 mg while the vehicle is being used for business, 50 mg in their own car off duty. If you hold a truck, bus, BE or work-vehicle licence, the law presumes you were driving that kind of vehicle until you show otherwise.

Towing a Trailer

A car towing a trailer with a maximum authorised mass of up to 750 kg, or a car and trailer whose combined maximum authorised mass is no more than 3,500 kg, is an ordinary category B vehicle: the general 50 mg limit applies to an experienced driver. A heavier combination that needs a BE licence puts you on 20 mg.

Novice Means 2 Years From Your First Full Licence

The 2 years run from the day your first full licence was issued. Adding a category later does not restart them. A learner permit only counts for the category of vehicle you are driving: a full car licence holder with a truck learner permit is on 50 mg in their car. Whether time on a licence from another country counts towards the 2 years is not settled for the drink-driving rule — if you are not sure, assume 20 mg.

The Penalty

Drink-driving over the limit carries a fine of up to €5,000, up to 6 months in prison, or both (section 4(5)).

No Change Announced

The Government’s Phase 2 Road Safety Action Plan 2025–2027 looks at alcohol interlocks as a sanction in some drink-driving cases, but contains no change to the limits. The learner permit renewal rules change on 1 November 2026; the limits and the 2-year novice period do not. As of 7 October 2026 no change to the limits has been announced.

Good to Know

An Irish standard drink contains 10 g of alcohol (HSE) — half a pint of 4.5% beer or a single spirit measure. You must be 18 to buy alcohol. In an emergency, 112 and 999 both work and are handled the same way.

Alcophone Has Ireland Built In

Pick Ireland and Alcophone shows every limit in mg/100 ml as well as %BAC. Settings › Driving has two switches: one for learner and novice drivers, and one labelled “Professional / towing / heavy vehicle” for trips in a truck, bus, taxi at work or with a heavy trailer — switch it off again when you are back in your own car. Whenever a switch lowers your limit, the app judges against the stricter number.