Performance
Does remapping affect your insurance?
Yes, and it has to be declared. Here is why insurers treat a remap as a modification, what usually happens to the premium, and what an undeclared one costs you.
Short answer: yes, and you have to tell them. Read the longer answer anyway, because the real risk is not the premium.
Why insurers care
An insurance policy is priced against the car described on it. Change the car, and the thing they priced is no longer the thing on your driveway.
A remap changes the calibration the engine runs on: fuelling, boost, ignition timing, torque limits. From the insurer’s point of view, that changes performance, and possibly how the car is driven and what a repair costs. Whether they think it changes it much is their call. Whether they get told is not optional.
Every proposal form asks some version of “has the vehicle been modified from the manufacturer’s specification?”. A remap is a modification. This is not a grey area and it is not one insurers are relaxed about.
What actually happens when you declare it
Usually less drama than people expect.
Ring your insurer or your broker, tell them the car has been remapped and roughly what has been done, and they will either adjust the premium, ask a few questions, or occasionally tell you they will not cover it.
Three broad outcomes:
- A small increase. Common for a Stage 1 on a diesel, or an economy tune on a van. Some insurers barely move.
- A meaningful increase. More likely on a performance car, a Stage 2, a young driver, or a policy that was already tight.
- A refusal. Some insurers simply do not want remapped cars. It means shopping around, ideally through a broker who knows the modified market.
The variation between insurers is large. Two companies looking at the same car can reach very different numbers, so one high quote is not the market’s answer.
The part that actually matters
The risk that matters has nothing to do with the premium.
If you do not declare a remap and you have a claim, the insurer can reduce the payout or refuse it entirely, and they can void the policy. A voided policy is worse than no policy: you then have to declare on every future proposal that you have had insurance voided, and that follows you for years.
Set the numbers side by side. Declaring might cost you some extra premium. Not declaring can cost you the value of the car, plus a third-party claim you are now personally exposed to, plus years of worse quotes.
There is no version of this arithmetic where hiding it wins.
“They will never know”
They might. It is not a good plan to build on.
Modern ECUs keep a record that they have been written to, and dealer diagnostic equipment reads it. Any main-dealer service or warranty investigation is an opportunity for it to be noticed. After a serious accident, an insurer paying out a large claim has both the motive and the right to have the car inspected.
So assume it is discoverable. If your case for not declaring depends on nobody looking, it is not a case.
What we do about it
Two things, and both are practical rather than legal advice.
We tell you. Every remap we do comes with the same conversation, because it is the most common thing people have not thought about. Policing your policy is not our job. Making sure you knew is.
We give you a way back. You can take a USB backup of your original file before we write anything. That is your car exactly as it left the factory, and it can go back on whenever you want: before you sell it, before a dealer visit, or if an insurer turns out to be difficult.
That backup is the reason a remap does not have to be a permanent decision. Take it even if you cannot imagine wanting it.
If the car is on finance or a lease
Check the agreement before you book anything.
On PCP, HP or a lease, you do not own the car outright, and most agreements require it to be returned in standard condition. A remap can put you in breach and produce a charge at the end of the term. Some finance companies will agree to it if you ask; some will not.
This is separate from the insurance question and it catches people out just as often. Same answer: read what you signed, and take the backup.
The short version
Declare it. It is a five-minute phone call, the cost is usually modest, and the alternative is a risk far larger than the money you were trying not to spend.
If you want to talk through what a remap would mean for your car before committing to anything, send us the registration and we will tell you what we would actually do with it.
Common questions
Will my premium definitely go up?
Not definitely, but expect it to move. Some insurers barely react to a Stage 1 on a diesel; others treat any ECU change as a significant risk. A few will not cover a remapped car at all, which you want to know before you book rather than after.
What if I bought the car already remapped?
You still have to declare it. The obligation is about the state of the car you are insuring, not about who changed it. If you are not sure whether a car has been mapped, the ECU can be read and you will know.
Can I just put the original file back before I claim?
No. Putting the original file back to get a claim paid is an attempt to deceive an insurer, and ECUs log writes anyway. Declare it.
Does an economy tune count?
Yes. Insurers ask whether the vehicle has been modified from manufacturer specification, and a calibration written for fuel efficiency is still a change to the ECU.
Do I need a specialist insurer?
Sometimes. Mainstream insurers vary a lot in how they handle modifications, and a broker who deals with modified cars will often find a better price than ringing round yourself.
Next step
Let's get you a price
Tell us what you drive and what you want done to it. We will come back with a price for your car, not a range off a chart.