Do You Have to Declare a Remap to Your Insurer?
Yes. A remap is a modification and a material fact, so it has to be declared. Skipping it is the fast way to have a claim refused or the policy voided.
A remap must be declared to your insurer. It changes the engine’s output, which changes the risk being priced, so it is a material fact under the Consumer Insurance (Disclosure and Representations) Act 2012. Declaring it usually raises the premium; not declaring it can void the whole policy, including unrelated claims.
Applies to the UK. Road-legality and inspection tests differ by country, so confirm the rules where you drive.
Whether a remap is road-legal and whether you have declared it are two separate things. It can be perfectly legal and still sink a claim if your insurer did not know about it. Declaring it is not optional.
Why a remap must be declared
Remapping changes the engine’s power and torque, and often the way the car drives, which is exactly the kind of change an insurer prices for. Under the Consumer Insurance (Disclosure and Representations) Act 2012 you must take reasonable care not to misrepresent the car, so if you are asked about modifications you have to include the remap. It counts even if the power gain is modest, and even if a previous owner had it done.
What happens if you do not
An undeclared remap that is relevant to a claim lets the insurer reduce the payout, refuse the claim, or treat the policy as if it never existed and void it. A voided policy is not limited to engine damage: it can wipe out an unrelated theft or third-party claim too, and driving on a voided policy is itself an offence. The saving from not declaring is tiny next to an unpaid claim.
How to declare it
Tell your insurer before you drive on the new map, not after something happens. Give the honest detail: what stage or power figure, who did it, and whether any supporting work went with it. Most mainstream insurers will cover a sensibly remapped car, sometimes for a small premium; if yours will not, a specialist modified-car insurer usually will. Keep a note of the date you declared it. Whether the map itself is road-legal, including the diesel DPF rules, is covered on the ECU remap legality page.
The conditions that matter
- !A remap is a material fact you must declare to your insurer.
- !It counts even at low power gains, and even if a previous owner had it done.
- !Declare it before driving on the new map; specialist insurers cover modified cars.
- ✕An undeclared remap can void the policy, including unrelated claims.
Sources
General guidance, not legal advice. Insurance terms vary by insurer and by exact vehicle and change over time; confirm with your insurer before modifying.