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Modified car insurance

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Car insurance for modified cars 

Has your car been altered since it was manufactured? If so, it’s considered modified. Find out how to insure a modified car and get the right deal for your needs and budget.  

What counts as a car modification?

A modification is any change you make to your car that alters it from the manufacturer’s standard settings. Modifications tend to fall into two categories: performance or cosmetic.

Performance car modifications include altering your suspension, changing the wheels, increasing horsepower, turbo upgrades, re-engineering your engine, chip tuning and remaps, intake and exhaust upgrades, handling modifications, lowering the suspension, fuel upgrades and transmission modifications.   

Cosmetic car modifications include go-faster stripes, body kit amendments, sunroof installation, tinted windows, specialised paintwork and speaker systems.

What are the most popular types of car modification?

We’ve pulled together some of the most popular modifications:  

  • Engine – changing the engine’s performance can dramatically increase the speed of a vehicle and make it practically a different car in the eyes of an insurance provider.
  • Wheels – adding bigger wheels and shiny alloys can affect handling and make your car a target for thieves. Try to use the vehicle manufacturer’s approved tyres when they need replacing.
  • Tinted windows – as long as they’re the right side of the legal limits, changing the windows shouldn’t impact too highly on your insurance. The added privacy can even be considered a crime deterrent by some insurance providers.
  • Stickers – even a sticker could be classed as a modification. A reverend in Wales was warned by her insurance provider that the religious messages she stuck to her car could invalidate her insurance policy.
  • Bodywork – adding anything expensive to a vehicle increases its value and will need to be declared as soon as it’s installed. Changing the body of the car can affect its aerodynamics and safety in the event of an accident.
  • Spoilers – a good spoiler will improve handling when travelling at high speeds. But it also increases the chances of speeding. If you do fit a new spoiler, ensure it doesn’t block the view from the rear window and is fitted securely by a qualified mechanic.
  • Parking sensors – these are designed to reduce the risk of minor bumps, which account for the vast majority of claims. This type of modification could mean you’re seen as a safety-first driver, which may reduce your premiums.
  • Exhaust – changing the exhaust system could enhance the performance of the car. Any changes to the original performance can affect the speed of your car, and insurance providers see this as a risk.

Some cars can also be modified to make them easier to use for drivers with disabilities, such as wheelchair ramps and lifts, altered foot pedals, hand controls and steering aids.

How do car modifications affect the cost of insurance?

All modifications, no matter how minor, have the potential to affect the cost of your car insurance. In many instances, car modifications could lead to higher premiums. But the good news is that not all car insurance for modified cars comes with sky-high costs.  

Why does it cost more to insure a modified car?

The cost of your insurance premium is based on the probability of you making a claim. So, when it comes to modifications, insurance providers will consider the following factors:

  • If the modifications increase the value of your car, the insurance claims you make could be higher as it’s often more expensive to repair or replace parts. 
  • If you’ve made your car faster, it could increase the risk of you being involved in a speed-related accident. 
  • Your car may be at greater risk of theft, especially if you’ve had expensive tech installed or you’ve modified its performance. Insurance providers could also assume that any modifications that alter the manufacturer’s standard settings can’t be guaranteed and may affect the car’s integrity. 
  • Young drivers are statistically more likely to claim on their insurance, so any modifications they make could raise their premium even more.

Don't forget, if you modify your car during the insurance term you need to notify your insurance provider about the change. This may alter the cost of the premium and you may also be charged an amendment or service fee. Check with your provider before you alter your car, to see how it’s likely to affect your premium.

How does modified car insurance work?

As well as covering everything that regular car insurance would – accidental damage and injuries to third parties, for example – modified car insurance can also cover all the extra parts and accessories on your car. 
 
If you have a car that’s particularly precious because of its modifications, you might want a policy offering special conditions if it’s written off. An agreed-value policy will give you a set value for your vehicle, rather than the average market value. And a salvage retention clause allows you to buy back what remains of your car and its parts, if it’s a total write-off. 

What does modified car insurance cover?

Insurance for modified cars will cover you for the same risks as any other car insurance policy. If you’d like to take out modified car insurance that covers your car plus its various modifications, unsurprisingly, it’s going to cost you more.

You can also take out the usual optional extras with your modified car insurance. Breakdown cover is a common example, while you may also want a courtesy car if yours is being worked on. Other examples include lost keys cover, windscreen cover, as well as no claims discount protection.

While you will be able to insure a modified car quite easily, you need to make sure that your modifications are legal. If any of them break the law, you won’t be able to get cover at all. Some common examples of illegal modifications include neon lights under the car and overly tinted windows (they must let in at least 70% of light).

How can I save on modified car insurance?

It might not always be easy to get cheap modified car insurance, but there are ways of reducing the cost of your car insurance premium, whatever type of car you have. Cutting down on your mileage, parking your car off the road and increasing your excess – provided you can afford it – can all help.

If you want to know how any particular modification will affect your insurance, then you should check with your insurance provider. And if you’re still keen on modifying your car, our comparison service lets you declare the changes you’ve made up front. So you know the price you’re offered will include any modification you’ve made.

Compare car insurance quotes today and see what deals are available for modified cars.

How is the value of a modified car calculated?

In most instances, a car’s value will increase as a result of its modifications – hence the reason why modified car insurance is more expensive than a standard policy. Considering how varied modifications can be, there’s no straightforward way to calculate a modified car’s value. This is why most modified car owners take out an agreed-value policy with their chosen insurance provider. This means that you and your provider agree on an amount that they’ll pay out in the event your car is written off, regardless of its original market value.

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Frequently asked questions

What modifications could help lower my car insurance?

Here are some modifications that could lower your premium:  

  • parking sensors – these can lower the risk of minor bumps.  
  • security measures – by fitting an immobiliser or tracking device, potential thieves could be discouraged.
  • tow bar – if you use your car for towing a caravan, horse box or trailer you’re likely to drive more slowly and carefully, so a tow bar could lower your premium. But insurance providers might consider towing to be an added risk. It’s worth checking with your provider before you get one fitted.
  • tinted windows – insurance providers’ opinions tend to be divided on tinted windows. Some consider them a cosmetic modification and could raise your premium. Others see them as a security measure, since they can prevent opportunistic thieves from seeing what’s inside.

What if my car comes with modifications?

If you’ve bought your new car from an authorised dealer and opted for extra features, such as alloy wheels, it shouldn’t affect your premium too much as they’ll have been fitted according to the manufacturer’s specifications.

However, if the modifications increase the value of your car, you may pay a slightly higher premium than you would for the basic model.

If you're buying a second-hand vehicle that’s been modified, make sure you get all the details of the modification and pass them to your insurance provider.

Can you make modifications mid-policy?

Yes, you can make modifications to your car mid-policy.

Just be sure to notify your insurance provider of any new modifications as soon as possible. Don’t wait until it’s time to renew. If you neglect to inform them and you need to make a claim, your policy could be invalidated.

Be aware that your premiums could increase as a result of the modifications, so it’s worth weighing this up before deciding to make them.

Will I need specialist modified car insurance?

If you modify your car, it’s possible you’ll need specialist modified car insurance.

Cars fit into one of 50 insurance rating groups, to help insurance providers work out where to set your premium. Any modifications to your car could mean it no longer conforms to its original insurance group and might invalidate a standard insurance policy. A specialist policy could cover you for even the smallest changes.  

Is modified car insurance more expensive for young drivers?

Just like regular car insurance, young drivers usually pay far more for their car insurance.

Combine this with modifications, and your risk as a young driver amplifies the cost further.

What do I need to get a quote?

To compare quotes with us, you’ll need to give us some details about your car including:

  • your registration
  • your no claims discount
  • any additional drivers you want to include in your policy.

We’ll also need a few personal details, like your age, address and occupation. If you’ve compared with us before, we’ll fill those in for you. We’ll then show you a list of quotes to compare.

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Author image Julie Daniels

What our expert says...

“Always be sure to make your insurance provider aware of any modifications as these could affect your premium”

- Julie Daniels, Motor insurance expert

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[2] As of January 2nd 2025, Compare the Market had an average rating of 4.8 out of 5 from 64,551 people who left a review on Trustpilot. The score 4.8 corresponds to the Star Label ‘Excellent’.

[3] Correct as of December 2024.

Page last reviewed on 13 JANUARY 2025
by Julie Daniels