Ireland → United Kingdom

Driving in the UK when you know Ireland

Differences first, worst-to-get-wrong first. Rules that match are folded away at the bottom.

Driving to the UK from Ireland: what to check before you go

These are the key destination rules to check first. The comparison below shows every verified difference. Follow local signs and instructions on the road.

Which side of the road do you drive on in the UK?: In the UK you drive on the left.
What is the speed limit in the UK?: 70 mph on motorways, 70 mph on dual carriageways, 60 mph on country roads and 30 mph in towns and cities. Those are the national default limits, which apply where no sign says otherwise.
What is the drink driving limit in the UK?: The legal limit in the UK is 80 mg/100ml. England and Wales. Scotland uses a lower limit.
What do you have to carry in your car in the UK?: Nothing. The UK requires no equipment by law.

Read the full driving rules in the UK and the required car equipment in the UK .

Looking to rent a car? Rental agencies often have there own rules on driving ages and equipment, make sure you check with them before you travel.
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What's different (12)

Speed limit on the motorway

Critical

Ireland · home120 km/h — about 75 mphChecked 6 Aug 2026

UK · destination70 mph — about 113 km/hChecked 3 Aug 2026 · official source

Speed limit on country roads

Critical

Ireland · home80 km/h — about 50 mphRegional (R-numbered) roads. Small local (L-numbered) roads are 60, not 80, and have been since February 2025. Look for the white circle with five diagonal black lines and a "Go Mall / Slow" plate — that sign means 60.Checked 16 Aug 2026

UK · destination60 mph — about 97 km/hSingle carriageway roads.Checked 3 Aug 2026 · official source

Speed limit in towns and cities

CriticalVaries by region

Ireland · home50 km/h — about 31 mphCouncils are cutting town centres and housing estates to 30, one area at a time, with a target of March 2027. Read the signs rather than assuming 50.Checked 16 Aug 2026

UK · destination30 mph — about 48 km/hEngland and Scotland. Wales uses 20 mph as the default in built-up areas.Checked 3 Aug 2026 · official source

Wales20 mph — about 32 km/hThe default in built-up areas. Some roads are signed back up to 30.Checked 3 Aug 2026 · official source

How much alcohol you may have in your blood

CriticalVaries by region

Ireland · home50 mg/100mlMuch stricter than Great Britain's 80 — a pint can put you over here.Checked 6 Aug 2026

UK · destination80 mg/100mlEngland and Wales. Scotland uses a lower limit.Checked 3 Aug 2026 · official source

Scotland50 mg/100mlChecked 3 Aug 2026 · official source

Speed limit on a dual carriageway

Important

Ireland · home100 km/h — about 62 mphThis is Ireland's national road limit — the green-signed N roads, dual carriageway or not. A cut to 80 on national secondary roads is in the Road Traffic Act 2024 but has not started, so 100 still applies.Checked 16 Aug 2026

UK · destination70 mph — about 113 km/hChecked 3 Aug 2026 · official source

Speed limit when towing a trailer or caravan

Important

Ireland · home

Motorway — 80 km/h
Dual carriageway — 80 km/h
Country roads — 80 km/h

Towing a trailer or caravan caps you at 80 wherever the ordinary limit is higher, the motorway included.Checked 16 Aug 2026

UK · destination

Motorway — 60 mph
Dual carriageway — 60 mph
Country roads — 50 mph

Checked 3 Aug 2026 · official source

Height below which a child needs a child seat

Important

Ireland · home150 cmOr under 36 kg. Licensed taxis are exempt.Checked 6 Aug 2026

UK · destination135 cmUntil 135 cm tall or age 12, whichever comes first.Checked 3 Aug 2026 · official source

Largest motorbike or scooter you may ride on a car licence

Important

Ireland · homeNone — you need a motorcycle licenceA car (category B) licence covers no moped or motorcycle. The RSA says a learner permit is required for category AM even if you hold a full licence in another category such as car, van or truck. One exception, stated on the RSA's licence categories page: an Irish B licence issued before 21 October 2006 carries AM, as long as it has not been expired for more than 10 years. The RSA does not say whether foreign B licences get any moped allowance.Checked 2 Sep 2026

UK · destination

Engine up to 50 cc

A full car licence lets you ride a moped up to this engine size without L plates or a moped test. If you passed your car test on or after 1 February 2001 you must first complete a compulsory basic training (CBT) course. Anything larger needs CBT and the motorcycle tests. The Highway Code's Annex 2 defines the two-wheeled moped class by a maximum design speed of 45 km/h (28 mph) rather than by engine size; that figure is not on the page cited here. Stated for licences issued in Great Britain; the source does not say whether foreign car licences get the same allowance.Checked 2 Sep 2026 · official source

How you pay for motorways

Important

Ireland · home

Toll booths
Electronic tolls with no barriers

Most tolls are barriers taking cards or cash. The big exception is Dublin's M50: no barriers, cameras only — pay online or at a Payzone shop by 8pm the NEXT day, or penalties go to the rental company. Rental cars often carry a tag; ask when you collect the car.Checked 6 Aug 2026

UK · destination

Toll booths
City charges

Almost all motorways are free. The M6 Toll and several bridges and tunnels charge. London and Durham charge to drive in the city centre.Checked 3 Aug 2026 · official source

Smallest motorbike allowed on the motorway

Good to know

Ireland · home

Engine at least 50 cc
Top speed at least 50 km/h

Framed by vehicle rather than class. The Rules of the Road list what must not enter a motorway: vehicles with an engine capacity of 50 cc or less, so exactly 50 cc is still barred and a machine must be bigger than that; and vehicles incapable of a speed of at least 50 km/h, so being able to reach 50 is enough. The book says "capable of a speed", which is recorded here on the design speed axis. Riders without a full licence for their category are barred too, and a category AM licence never allows motorways.Checked 2 Sep 2026

UK · destination

Engine at least 50 cc
Power at least 4 kW

The rule is set by engine size, not vehicle class: riders of motorcycles under 50 cc (4 kW) must not use motorways, so a machine of exactly 50 cc is allowed. The Highway Code gives the power figure in brackets as the equivalent of the engine size rather than as a separate test. Riders holding only a provisional motorcycle licence must not use motorways either.Checked 2 Sep 2026 · official source

What you should carry, but do not have to

Minor

Ireland · home

Warning triangle
First aid kit
Fire extinguisher
Spare bulbs

Advised by the Road Safety Authority, not required by law.Checked 20 Aug 2026

UK · destination

Warning triangle
First aid kit
Fire extinguisher
High-visibility vest

Advised, not required. One motorway exception is worth knowing: do not set a warning triangle out on a motorway hard shoulder — get behind the barrier instead.Checked 20 Aug 2026 · official source

Typical fines

Minor

Ireland · home

Minor speeding — fine from 160 EUR, 3 points (The fixed charge notice. It becomes 240 euro if unpaid after 28 days, and 320 euro plus a court date after 56 days.)

Checked 16 Aug 2026

UK · destination

Holding a phone — fine from 200 GBP, 6 points (Drivers who passed their test within the last 2 years lose their licence instead.)

Checked 3 Aug 2026 · official source