Are Speed Limiters Mandatory on New Cars in the UK?

Not yet in Great Britain, but it is coming. Intelligent speed assistance has been required on new cars in the EU since July 2024, and many new cars sold here already have it. In July 2026 the government confirmed it will make the technology a requirement for new vehicles in Great Britain. Used cars are not affected.

What is intelligent speed assistance?

Intelligent speed assistance, or ISA, is often called a speed limiter, but that is not quite what it does. The car works out the speed limit using a camera that reads road signs, map data or both. If you go over the limit, it lets you know.

How it does that depends on the car. Some show a warning and sound a chime. Some make the accelerator pedal push back or vibrate. Some gently reduce power. In each case the driver stays in control and can override it.

What is the law in Great Britain?

The EU rules came into force after the UK left the EU, so they were not automatically required here. Many manufacturers fit the system anyway because they build cars to one specification for the UK and Europe.

In July 2026 the government published its decision to require a package of safety technologies, including intelligent speed assistance, for new vehicles approved for sale in Great Britain. The plan is for the rules to apply to new models 12 months after the legislation comes into force, and to all newly registered vehicles 24 months after. You can read the government's response on GOV.UK.

Does this affect used cars?

No. The requirement applies to new vehicles only. Nothing has to be fitted to a car that is already on the road, and there is no rule against buying or selling a used car without it.

If you are buying a recent used car, it may well have the system. Ask how it works on that model during the test drive, including how to adjust or override the warnings.

Is the system always right?

No. It can misread a sign, pick up a limit from a side road or miss a temporary limit. The driver is still responsible for keeping to the speed limit, whatever the dashboard says.

Common questions

Will the car stop you from speeding?

No. The system warns you or eases off the power, but you can override it by pressing the accelerator.

Is it the same as cruise control?

No. Cruise control holds a speed you set. Intelligent speed assistance reads the limit for the road and tells you when you go over it.

Does your current car need one fitting?

No. There is no requirement to retrofit it to a car that is already registered.

Looking for your next car in Barnsley?

Browse our used cars or call the Sales team at anycolourcar.com on 01226 574410. Our test drive checklist covers what to try before you buy.

This guide is general information, not legal or financial advice. Updated October 2026.