Is remapping legal in the UK? MOT, insurance and the law
A remap is legal in the UK — but there are three things you must get right. Here is the straightforward version.
By RevX Workshop
The short answer
Yes. A calibration that keeps the vehicle within UK construction and use regulations is legal, and the car will still pass an MOT.
What you must do
Tell your insurer. A remap is a modification and must be declared. We provide a written before-and-after power and torque summary you can forward to them.
Keep the emissions equipment fitted. A Stage 1 or Stage 2 calibration does not require removing a DPF, EGR valve or catalytic converter, and it does not need to.
Stay road-legal on noise. A standard calibration does not change exhaust noise. Overrun calibrations can, so check the limits before booking one.
What about the MOT?
The MOT tests emissions, braking, lights, structure and safety systems. A vehicle with a correctly written calibration and functional emissions equipment passes exactly as it did before.
The emissions grey area
DPF and EGR software options are a different category altogether. They are supplied for motorsport, export and off-road use only and are not legal for UK road use. We will always tell you which category your request falls into before any work is booked.
If you are not sure, ask
Send us your vehicle details and what you are hoping to achieve. If something is not legal for the road, we will say so plainly — and suggest a legal alternative.
Ready to calibrate your car?
Check the estimated gains for your vehicle, or send us a request and we will confirm what is possible.