Cars
Car insurance for modified cars: what a specialist policy covers
Car insurance for modified cars explained: what you must declare, how mods are valued, common exclusions and what to check in the policy wording.
Car insurance for modified cars is a motor policy arranged on the basis that your car has been changed from the manufacturer's standard specification, with those changes declared to and accepted by the insurer. It means the car is insured as it actually is, but it does not automatically mean every aftermarket part is covered for its full value, so the detail is in the policy wording.
What is modified car insurance?
The Financial Ombudsman Service describes a modification as a change that is not part of the manufacturer's standard specification. Some are simple, such as changing alloy wheels. Others, like engine tuning or an upgraded exhaust, are more involved.
Insurance for modified cars is not a separate legal category. It is ordinary UK motor insurance (third party, third party fire and theft, or comprehensive) where the insurer has been told about the changes and priced and worded the cover around them. Common examples of modifications include:
- Alloy wheels of a different size or style from standard
- Engine remaps, ECU changes, air filters and exhaust systems
- Spoilers and other styling changes
- Tinted windows
- Audio and in-car entertainment upgrades
The Ombudsman has warned that even seemingly minor changes such as tinted windows or stereo upgrades can lead to higher premiums because they change the risk.
How does modified car insurance work?
When you ask for a quote, you are asked to list the modifications. The insurer uses that information to decide whether to offer cover, on what terms and at what price. The Ombudsman notes that modifications can change the risk, for example by making a car more likely to be stolen.
The legal duty here comes from the Consumer Insurance (Disclosure and Representations) Act 2012. You must take reasonable care not to give the insurer wrong information when you take out or change a policy. If you get it wrong, what the insurer can do depends on why:
| Type of misrepresentation | What the insurer can do under the Act |
|---|---|
| Deliberate or reckless | Treat the policy as if it never existed, refuse all claims and, in general, keep the premiums |
| Careless, and the insurer would not have offered cover at all | Treat the policy as if it never existed and refuse claims, but it must refund the premiums |
| Careless, and the insurer would have offered cover on different terms | Treat the policy as if it had those terms |
| Careless, and the insurer would have charged more | Reduce a claim payment in proportion to the premium it would have charged |
The Ombudsman's cases show how this plays out. In one, a driver whose alloy wheels were three inches larger than standard had their policy reinstated, because the Ombudsman accepted that an average person would not have noticed. In another, the Ombudsman found an air filter change was not a reportable modification and had a negligible effect on performance, so the insurer was told to reinstate the policy and settle the claim. But where a driver knew about an ECU remap and exhaust retune and did not declare them, voiding the policy was found fair. The Ombudsman's summary is blunt: if you did not declare a significant modification and the policy clearly asked you to, a complaint is unlikely to be upheld.
The same applies to changes made before you owned the car. The Ombudsman says owners should tell insurers about modifications "even if they were made before the car was purchased", so it is worth checking a used car's history before you buy it.
What does a modified car insurance policy actually cover?
Declaring a modification gets the car insured. Whether the modified parts themselves are paid for after a claim is a separate question. The Ombudsman has seen owners who declared their modifications and paid more for cover, only to find when they claimed that the value of the modification was not covered.
So when you read a modified car insurance policy, look at these areas.
A limit on the value of modifications
Some policies set a maximum amount they will pay for modifications, separate from the value of the car. If you have spent more on parts than that limit, the difference is not covered. Check whether there is a limit, what it is, and whether it applies per item or in total.
How damaged parts are replaced
Check what the wording says about replacing modified parts after a claim. Some policies may only pay to put the car back to its standard specification, while others will replace a part with the same or an equivalent one. For example, if aftermarket wheels are damaged and the policy only covers standard parts, you could get the cost of the original wheels rather than the ones you fitted.
Excluded uses such as track days and shows
Policy wording may exclude use on a race track, at a timed event or a track day, or set conditions for taking the car to shows. If you plan to do any of these, find out in advance whether the policy covers it, as an exclusion means a claim arising from that use is not paid.
What you must tell the insurer during the policy
The 2012 Act's duty of reasonable care applies when you take out or change a policy, but many motor policies include a condition asking you to tell the insurer about changes during the policy. In published decisions, the Ombudsman has generally said an insurer should only change or cancel cover over a mid-term change that is fundamental to the risk, giving a significantly more powerful engine as an example. The Ombudsman also advises telling your insurer about any changes as soon as possible. Read the condition in your own policy so you know what to report and when.
What to check in the policy wording before you buy
These steps help you see what you are actually getting:
- List every change to the car, including anything done by a previous owner. Keep receipts and photos.
- Answer each question on the proposal honestly and in full. If you are not sure whether something counts as a modification, ask.
- Read the policy's definition of "modification" so you know what it includes.
- Find any limit on modifications cover and compare it with what the parts cost.
- Check how modified parts are replaced or valued after a claim.
- Look at the exclusions for track days, racing, timed events and shows.
- Check the condition about telling the insurer about changes during the policy.
- Make sure your statement of facts lists the modifications correctly once cover starts.
Our insurance quote checklist covers the other details you are usually asked for.
Legal rules that sit alongside modified vehicle insurance in the UK
Some modifications raise legal issues as well as insurance ones.
Tinted windows. GOV.UK says that for vehicles first used on or after 1 April 1985, the front windscreen must let at least 75% of light through and the front side windows at least 70%. For vehicles first used before that date, both must let at least 70% through. There are no rules for the rear windscreen or rear passenger windows. If the front glass is too dark, you could get a prohibition notice stopping you using the car until the tint is removed, or a penalty notice or court summons.
Structural modifications. You must tell DVLA if you make a structural modification, meaning a change to the chassis, monocoque bodyshell or frame that alters the vehicle's dimensions or appearance. Examples include cutting or lengthening roof pillars, removing the roof and drilling extra holes within 30cm of a suspension, steering, braking or seatbelt mounting point. Converting a vehicle to run on electricity must also be reported, even if its appearance does not change. You notify DVLA using form V627/3, and GOV.UK also reminds owners to make sure their insurance is still valid after the change.
What affects the price of car insurance for modified cars?
The price depends on the same things as any car insurance (the driver, the car, where it is kept, claims history) plus the modifications. Changes that make a car faster, more attractive to thieves or more expensive to repair can all affect the premium.
People sometimes look at fitting better security, adding a higher voluntary excess or limiting who drives the car. Each has trade-offs, and our guide on how to reduce car insurance without invalidating your policy explains what to watch for. Leaving a modification off the form to bring the price down is the one approach that can leave you with no cover at all when you need it.
If you would like to speak to a specialist, you can get modified car insurance quotes by filling in a short form, and an FCA-authorised broker from the Kompare panel will contact you with quotes. Kompare does not give advice or compare prices; the broker talks you through the options.
What if a claim is refused because of a modification?
If you think it has acted unfairly, complain to the insurer first. If you are unhappy with its final response, the Financial Ombudsman Service can look at the complaint for free. It considers what the policy says, whether you took reasonable care when applying, and whether the insurer treated you fairly. Where it finds the insurer got it wrong, it can tell the insurer to put things right and may award compensation for distress and inconvenience.