Car mods that don’t affect insurance

As reported in The Sun, Tempcover research has revealed just how easy it is to fall foul of the UK's modification rules without realising. In fact, 1.5 million UK drivers could be driving on invalid insurance, simply because they didn't declare a modification - even something as small as a plug-in Apple CarPlay adapter.

Failing to disclose basic car modifications (as reported in both mirror.co.uk and express.co.uk) could void an insurance policy in the event of an incident. This can include paint protection products, new alloy wheels and even stickers or decals.

According to Auto Express, stickers that declare allegiance to a football team or political party could potentially make your vehicle a target for vandalism.

The most important thing to remember is to declare any car mods you make to your insurer. They can then charge any extra policy fees and confirm you are fully covered.

New research: 1.5 million drivers risk losing cover over undeclared tech and cosmetic changes

Tempcover surveyed 2,000 UK motorists and found a quarter (25%) drive a car with at least one non-factory modification.

Confusion over what actually counts as a “modification” means 14% of those drivers (around 1.5 million people nationally) haven't declared their changes to their insurer, putting them at risk of reduced payouts or a voided policy.

Much of the confusion comes from digital retrofits rather than obvious performance mods. Google Trends shows UK searches for wireless CarPlay adapters have surged since 2024 and recently hit an all-time high, as plug-and-play gadgets have made it easier than ever to upgrade a car's tech without a garage visit.

But most drivers don't realise this still counts as a modification that needs declaring.

Modifications drivers most commonly don't know they need to declare:

• Unofficial Apple CarPlay, Android Auto, or touchscreen retrofits - 91% unaware
• Non-factory parking sensors - 88% unaware
• Upgraded sound system or speaker installations - 88% unaware
• Retrofitted parking sensors - 87% unaware
• Paint protection film (PPF), vinyl wraps, or body stickers/decals - 86% unaware
• Installed towbars or roof racks - 86% unaware
• Bulb replacement with brighter aftermarket lights - 82% unaware
• Aftermarket alarms, immobilisers, or GPS trackers - 78% unaware
• Non-factory alloy wheels, custom paint, or tinted windows - 77% unaware
• Engine ECU remapping, chip tuning, or pedal boxes - 72% unaware

Of the drivers who didn't declare a modification, 39% didn't realise aftermarket additions counted as an official modification at all, while 19% assumed small cosmetic or digital changes (e.g. a retrofitted CarPlay unit or parking sensors) were exempt from the rules.

What counts as a modification for car insurance?

Not all modifications affect the price of car insurance. Ones that increase your security can potentially lower your price while external modifications like a properly fitted roof rack also shouldn’t make too much difference.

Having said that, it’s still a good idea to let your insurance company know to ensure you’re properly covered. This now includes tech add-ons, not just visible bodywork changes.

Tempcover's research found that 88% of drivers didn't know an upgraded speaker system needed declaring, and 77% aren't aware that non-factory alloy wheels, custom paint or tinted windows also must be disclosed.

The following add-ons – which are all designed to enhance the security of your car – can also help bring the price of your policy down:

• Speed limiters (these are now fitted in cars manufactured in the EU, but need to be activated)
• Alarms
• Trackers
• Immobilisers

Performance modifications (e.g. alloy wheels and suspension changes) and adding in-car entertainment systems can increase the cost as insurance companies are likely to consider these as changes that put you at higher risk.

Confused.com states that car modifications can increase your insurance premium because they can:

• Increase the value of your car, making it more desirable to thieves
• Make your car more powerful, meaning there’s more chance of an accident

If you want to make a modification (no matter how small) during your policy, you should contact the insurance company for confirmation of how much this will affect the price. You should do this before doing anything to your car, just in case it hugely increases your premium or means your insurer can no longer cover you.

Is not declaring a modification the same as insurance fraud?

Not necessarily, but there are definitley some grey areas. Tempcover's research found that over half (52%) of drivers incorrectly believe failing to declare a modification is automatically a criminal offence, while just 17% correctly say it isn't, and a third (31%) simply don't know either way.

An honest slip-up like forgetting to mention a modification, or not realising it counted as one, is generally treated as careless misrepresentation, which can see a claim payout reduced or your policy terms changed.

It only tips into insurance fraud if you deliberately hide a modification to deceive your insurer.

Tempcover's research found drivers are largely unaware of just how serious the consequences can be:

• 47% don't know an insurer can void a policy entirely if they can show they wouldn't have offered cover at all had they known about the modification
• 82% don't know that driving on an invalidated policy risks an IN10 conviction and 6 to 8 penalty points
• 79% don't realise an undeclared or fraudulent modification can lead to a five-year listing on the Insurance Fraud Register (IFR), making it far harder to get insured again
• Only 27% understand that a voided policy could leave them personally liable for third-party financial damages