Modified Vehicle Insurance

Have you had your car altered since it was manufactured? If so, you have a modified car and this may impact your insurance.

In this guide, we’ll detail what modified car insurance is and how it differs from standard car insurance. We’ll look at what it covers and how you can find the best insurance for modified cars.

Four young friends sat in a silver car looking out of the car window
12 Apr 2024

How do modifications affect car insurance?


Whilst most people are happy to drive their car exactly as it was manufactured, some car lovers want to enhance the looks and the performance of their motors. But these modifications can have an impact on how you insure your altered or customised car.


If you have an altered car, you’ll most likely have to insure it with a dedicated modified car insurance policy. This kind of car insurance works in the same way as standard car insurance, except the policy will note and cover the modifications you’ve made to your motor.


How does modified car insurance work?


Car insurance for modified cars works in the same way as standard car insurance, except it acknowledges and covers the alterations you’ve made to your car.


To get a proper quote – and to make sure you buy the right modified car insurance – you’ll need to tell insurance providers about all the changes you’ve made to your car that alter its appearance and performance.


The insurance policies you’re quoted for will then include cover for the changes and will likely alter your premium based on any changes to the value of your car. Modifications can make car insurance more expensive, but not always. Simple modifications – like roof bars or a tow ball – may have no impact on price, whilst more extensive modifications will.


If you have a car that you’ve devoted considerable time and money to customising, you may want to consider a policy that has:

  • An agreed value clause: In the case your car is stolen or written-off, this ensures you receive an agreed amount of compensation for your car rather than its market value, which may be less.
  • A salvage retention clause: This allows you to buy back what remains of your car after an accident that writes it off, so you can recover its parts.


What counts as a car modification when insuring your car?


Any car with an alteration that changes it from the manufacturer’s specification counts as modified. The seven categories that cover most car alterations are:


  1. Security and safety modifications: Including added alarms, trackers, immobilisers and parking sensors and cameras.
  2. Cosmetic modifications: Like new wheel alloys, vinyl wraps, resprays and tinted windows.
  3. External and visual modifications: Such as towbars, roof racks or bars, additional lights, and adaptive headlights.
  4. Bodywork modifications: More extensive appearance changes that include spoilers, bumpers, body kits, roll bars and side skirts.
  5. Sound and entertainment modifications: Including installing a new sound system and sound system components. This also includes in-car entertainment devices, like TV screens and even games consoles.
  6. Engine or mechanical modifications: Additions like non-standard exhausts, uprated brakes, lowered suspension, or engine alterations like dump valves.
  7. Disability modifications: Such as ramps, adapted handbrakes, tail lifts, and infrared controls.


All of these modifications can alter a car’s handling, performance, safety and value. Which can affect how your car will be insured.


Popular car modifications


You can see the seven categories of car modification above, but the most common car alterations include:


  • Engine alterations that improve the car’s performance
  • Wheel changes, like larger wheels and/or alloys
  • Tinted windows
  • Bodywork stickers – even relatively small cosmetic changes can count as modifications
  • Bodywork changes and additions, like spoilers and side skirts
  • Modified exhaust systems
  • Parking sensors and cameras


What does modified car insurance cover?


Modified car insurance policies in the UK cover you for all the same risks that standard car insurance will. But it also includes cover for your modifications and any change in value to the car.


Just like standard car insurance, you can buy different levels of cover. Typically:


  • Third-party cover: For third-party claims made against you.
  • Third-party fire and theft cover: For third-party claims made against you and for any damage or losses due to fire or theft.
  • Comprehensive cover: For third-party claims made against you plus compensation for any damage or losses to your car, even if you were at fault.


Individual policies will vary, but modified car insurance policies may also cover:


  • Additional named drivers
  • Personal accident cover
  • Theft of personal possessions from your car
  • Windscreen cover
  • Misfuelling (the cost of repairs after putting the wrong fuel in your car)
  • Cover to drive other cars
  • Breakdown cover
  • A courtesy car while yours is repaired
  • Driving abroad
  • Cover for legal costs


Why does insuring a modified car cost more?


Car insurance for modified vehicles often costs more than standard car insurance.


  • The modifications may increase the value of your car and/or make it more expensive to repair or replace parts, increasing the cost of any claims you might make.
  • If alterations have made your car accelerate faster or given it a higher top speed, it could increase the risk of an accident.
  • Your car may be at a greater risk of being stolen or vandalised.


How to calculate the value of a modified car for insurance?


The modifications you can make to a car vary, meaning there’s no straightforward or consistent way to calculate the value of an altered car.


Most modified car owners opt for an agreed-value policy with their insurance provider. You and your provider agree on an amount the car is worth in the event it’s written off or stolen and not recovered. This agreed amount is usually based on the market value of the car plus the approximate value of the modifications you’ve made.


How to save money on modified car insurance


Modifying your car may increase the cost of your premiums, but there are ways you can reduce the cost of car insurance. They include:


  • Agreeing to a maximum mileage: Agreeing to drive a certain number of miles per month can lower your premiums by showing you’ll only spend a certain amount of time driving.
  • Paying annually: Insurance policies are often cheaper if you pay in one annual sum rather than monthly instalments.
  • Increasing your excess: If you volunteer to pay more with each claim, your provider may offer you a lower premium.
  • Taking out a telematics policy: A black box is installed in your car that monitors how you drive. If you’re judged to be a safe driver, your premium may be lower when you renew it.
  • Parking your car securely: Your premium will be lower if your car is kept off the road and in a locked location, like a garage.
  • Fitting an immobiliser and a tracker: These additions can make your car harder to steal and easier to find if it has been taken.
  • Shopping around for your modified vehicle insurance: You’ll find the best modified car insurance policies if you compare quotes.


Compare modified car insurance quotes with Asda Money


If you’re looking for a better deal on your car insurance, you can compare quotes from some of the UK’s top insurance providers with Asda Money. The car insurance comparison service is provided by Vast Visibility Limited.

Modified car insurance FAQs

Is it expensive to insure a modified car?

Some modifications will make a car more expensive to insure, but some won’t. Minor cosmetic modifications, and additions like roof bars, often don’t. But modifications that alter a car’s body and its performance usually do. Inform car insurance providers of all modifications you’ve made to a car, and they can let you know how it will affect your insurance premium.

Do I have to tell my insurance if I modify my car?

Yes. You should inform your insurance provider of all the modifications you make to your car, no matter how minor you think they are. If you don’t, your insurance policy may be invalidated and your car may no longer be covered.


What happens if you don't declare modifications?

If you don't declare any modifications you’ve made to your car, it can invalidate your insurance policy, and your car may no longer be covered. If you have an insurance claim refused or a policy cancelled, it can make it harder and more expensive to buy insurance in the future.


It is also important to note that if any modifications mean that the vehicle no longer meets the emissions standards it was designed to meet, it is classed as an offence and you could end up paying a hefty fine.


Modifying your vehicle’s emissions: the legal, safety and health implications - GOV.UK (

Do body kits affect insurance?

Body kits are considered a modification, and one that usually increases your insurance premium. Body kits are typically made of polyurethane or fibreglass, meaning they’re likely to splinter or shatter during an accident.

Are stickers classed as a modification?

Insurance companies will differ, but many do consider bodywork stickers as a modification.

Does a dash cam count as a modification?

Whilst most insurance providers won’t consider a dash cam as a modification, some will. Check with your insurer if you add a dash cam to your car.

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