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A Professional's Perspective

How Do Car Modifications Affect Your Insurance? We Take a Look


Thinking about pimping your ride?

Before you go full throttle on those modifications, it's crucial to understand how they might affect your car insurance premiums and claims. From flashy spoilers to engine tweaks, modifications can be a mixed bag when it comes to your insurance cover.
We're here to clear the air, exploring everything you need to know about mods and their impact on your insurance. So, buckle up and get ready for a deep dive into the world of modified cars!

The Golden Rule: Talk to Your Insurer

Let's start with the most important takeaway: Always, always, always contact your insurer before making any modifications to your vehicle. This could save you from nasty surprises down the road if you need to make a claim. Plus, in some cases, certain modifications could even lower your premiums! It's a win-win.

What Exactly Is a Modification?

Defining a "modification" can be a bit of a grey area. Some insurers consider any change to your car's original state as a modification, while others focus on changes that affect its value, performance, appearance, or attractiveness to thieves.

What could an insurer consider a modification?

Wheels, Brakes and Suspension

  • Wheel spacers
  • Wheels - carbon
  • Wheels - magnesium
  • Wider tyres
  • Wider wheels
  • Trial tyres
  • Chassis changes
  • Fork braces
  • Forks – extended
  • Frame modified
  • Steering change
  • Suspension – airbag/hydraulic
  • Suspension – updated/lowered/stiffened spring & dampers
  • Suspension changes
  • Uprated anti-roll bars
  • Uprated brakes


  • Rear roof spoiler
  • Front or rear spoiler/airdam
  • Body kit
  • Rear valance
  • Paintwork/designs/decals
  • Murals
  • Graphics/decals - decoration/nonadvertising
  • Paint work – non standard
  • Paint work – race replica
  • Painted signs
  • Non-standard respray
  • Badges indicating increased performance
  • Stripes

Engine, trans & exhaust

  • Bored-out engine
  • Engine casing guards
  • Engine chip
  • Engine tuned
  • Carburettor changed
  • Chipping – engine management system changes
  • Dual controls
  • Exhaust system changes – cosmetic and performance
  • Induction kit (non-turbo or turbo)
  • Intercooler – any changes
  • Uprated cam
  • Stage 2 head
  • Stage 4 head
  • Uprated fuel injection
  • Water injection system
  • Gearing change
  • Blueprinting
  • Overdrive
  • Snorkel
  • Supercharging

Bodywork 2

Interior and Exterior Body Mods
  • Additional seating
  • Additional windows
  • Door poppers
  • Cabriolet conversion
  • Campervan conversion
  • Carbon fibre bonnet
  • Interior changes
  • Larger speakers
  • Petrol tank changes
  • Upholstery changes
  • Rear sets
  • Winch
  • Changing to a convertible
  • Bonnet bulge
  • Altered pedal configuration
  • Awning – added or upgraded
  • Fairings
  • Fibreglass panels
  • Luggage system/panniers
  • Roll bars
  • Roll cage
  • Seats - removal
  • Seats - replacement
  • Flared wheel arches
  • Flared wings
  • High roof
  • Hoist
  • Galvanised chassis
  • Emergency services blue light
  • Refrigeration
  • Pop up roof – added or upgraded
  • Side skirts/sills
  • Side steps
  • Road conversion
  • Tail lift
To avoid any confusion, it's crucial to check your insurer's specific definition of a modification. Their view is the one that matters most!

How Modifications Impact Your Insurance

Different modifications can have varying effects on your insurance premiums:
  • Lower Premiums:

    Safety-enhancing modifications like alarms, tracking devices, and parking sensors can actually make your car cheaper to insure.
  • Higher Premiums:

    Modifications that increase your car's value or make it more appealing to thieves, such as body kits, alloy wheels, and high-end entertainment systems, are likely to raise your premiums.
  • No Change:

    Some modifications, like floor mats, interior lights, and seat covers, might not affect your premiums at all.
The key is to check with your insurer before making any changes. They'll be able to give you an accurate estimate of how your modifications will affect your insurance.

How to Spot Modifications on a Used Car

Bow of a cargo ship cruising sea green calm seas
If you're buying a used car, it's essential to determine if any modifications have been made. Here are a few tips:
Ask the Seller: - (click to expand)
When purchasing a used car, it's crucial to gather comprehensive information about any changes or additions made since it was new. Here are some specific questions to ask:
  • Modifications: Inquire about any performance modifications, such as changes to the engine, exhaust system, suspension, or brakes. These can significantly affect the car's performance and insurance costs.
  • Aesthetic Changes: Ask about any cosmetic modifications, including changes to the paint, bodywork, wheels, or interior. These might affect the car's value and desirability.
  • Maintenance and Repairs: Have there been any major repairs or replacements, like a new transmission, engine rebuild, or significant electrical work? Ensure these were done by a reputable mechanic.
  • Aftermarket Additions: Check for any aftermarket additions like a new sound system, navigation system, tinted windows, or other electronic upgrades.
  • Documentation: Request any documentation or receipts for work done. This helps verify the legitimacy and quality of the modifications or repairs.

Visit a Dealership: - (click to expand)
Your car's main dealer is a valuable resource for identifying non-standard features and ensuring everything is as it should be:
  • VIN Check: Provide the Vehicle Identification Number (VIN) to the dealership. They can pull up the car’s original specifications and compare them to the current state.
  • Expert Inspection: Have a certified technician inspect the car. They can identify non-standard parts or modifications that might not be immediately obvious to an untrained eye.
  • Software Updates: Dealerships can check if the car’s software is up to date, especially important for modern cars with complex electronic systems.
  • Service History: Verify the service history with the dealership to ensure all scheduled maintenance has been performed and to check for any dealership-recorded modifications or repairs.

Consult Your Insurer: - (click to expand)
Providing your insurer with comprehensive details about the car and its potential modifications is essential for accurate coverage:
  • Detailed Information: Give your insurer a detailed list of all known modifications, including any performance enhancements, cosmetic changes, or aftermarket additions.
  • Impact on Premiums: Understand how these modifications might impact your insurance premiums. Performance enhancements, for instance, can increase premiums due to higher risk.
  • Coverage Adjustments: Ensure your policy adequately covers any high-value modifications or additions. You might need additional coverage for aftermarket parts.
  • Honesty is Key: Be completely honest with your insurer. Failure to disclose modifications can result in denied claims or cancellation of your policy.
  • Documentation: Provide any supporting documentation you have, such as receipts or records of modifications and maintenance, to help your insurer accurately assess the car’s value and risk.

By thoroughly addressing these points, you can make a more informed decision when purchasing a used car, ensuring that you understand its history, current condition, and any potential insurance implications.

What if My Insurer Won't Cover My Modifications?

If your current insurer refuses to cover your modified vehicle, don't despair! The British Insurance Brokers' Association (BIBA) can help you find a specialist insurer who caters to modified cars.

The Financial Ombudsman Service Weighs In

The Financial Ombudsman Service (FOS) has made rulings in favor of policyholders whose claims were initially denied due to modifications. If you have a dispute with your insurer about modifications, the FOS can help you resolve it.

Top Tips from Insurance Brokers

Our expert brokers offer these top tips for navigating the world of car modifications and insurance:
  • Communicate:

    Always keep your insurer in the loop about any modifications, whether planned or existing.
  • Review your documents:

    Double-check your policy to understand when and how to report modifications.
  • Do your research:

    If you're buying a used car, investigate any potential modifications with the seller or a dealership.
  • Check comparison sites carefully:

    If you use a comparison website, double-check the information on the insurer's website to ensure accuracy regarding modifications.
  • Save money where you can:

    Before investing in expensive modifications, ask your insurer if there are any safety or security upgrades that could potentially lower your premium.
By following these tips and understanding the impact of modifications on your insurance, you can enjoy your personalised ride with peace of mind.

Car Modifications and Your Insurance: FAQs

What car modifications affect insurance? - (click to expand)
The text indicates that modifications that can affect insurance include:
  • Modifications that lower premiums: alarms, tracking devices, and parking sensors.
  • Modifications that increase premiums: body kits, aftermarket wheels, and entertainment systems.
  • Modifications that may not affect premiums: floor mats, interior boot lights, and car seat covers.

It's important to note that the specific impact on insurance premiums will vary depending on the insurer and the specific modifications made to the vehicle.
Are car modifications illegal? - (click to expand)
Not all car modifications are illegal, but it's important to be aware that some modifications could potentially be illegal if they do not comply with UK road traffic regulations or compromise the safety standards of the vehicle. It's crucial to research and understand the legal requirements before making any modifications to your car.
What car modifications are illegal in the UK? - (click to expand)
The list of illegal car modifications varies and is subject to change. Consult the UK's road traffic regulations or seek legal advice for a definitive list.
What car modifications are there for disability vehicles? - (click to expand)
Modifications for disability vehicles often focus on improving accessibility and accommodating specific needs. These can include wheelchair ramps, hand controls, and adapted seating.
How much are car modifications? - (click to expand)
The cost of car modifications varies widely depending on the type and extent of the modifications. Simple ones can be relatively inexpensive, while extensive changes can be quite costly.

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    At Primo, we explain how car modifications can impact your insurance. Modifications can increase your premium due to heightened risk or vehicle value, but some may reduce costs by improving safety. We cover common modifications like performance enhancements, aesthetic changes, and safety upgrades, detailing their effects on insurance policies. Our guide advises on disclosing modifications to your insurer and understanding the implications to ensure proper coverage. This resource helps car owners decide about vehicle modifications and their insurance impacts.