Get personalised, not penalised with your car insurance

We all have personalities and different ways that we show them off. Some do it through their sense of dress style, some with their hobbies and some, with the look of their car.

For many, their cars are their pride and joy, and a lot of effort goes into keeping them tip top. For example, modifying your vehicle can make it feel more you, but did you know that some of these changes could affect your insurance? In some cases, failing to declare a mod could even lead to your claim being turned down. Yikes!

Don’t worry though, this blog will walk you through what counts as a modification, why it matters to your insurer, and how to keep your cover as customised as your car.

What Counts as a Modification?

In simple terms, a car modification is any change made to a vehicle that alters it from the manufacturer’s standard specification. That includes everything from engine remapping and aftermarket spoilers to cosmetic touches like tinted windows or alloy wheels.

Even modifications made before you purchased the car, (by a previous owner), need to be disclosed to your insurer. Why? Because insurers assess risk based on a vehicle’s specifications. Changes to those specifications could mean the risk, premium or even their acceptance of the car/cover might be different if they are informed of modifications.

The Most Common Oversight: Tinted Windows

Next time you’re out and about, look at how many vehicles have tinted windows. I did this the other day, and there were so many on the roads! One of the most frequently overlooked modifications is tinted windows. Many people assume this is a harmless aesthetic tweak, but heavily tinted windows—especially on the front side windows or windscreen—can be illegal depending on how dark they are.

In the UK, for example:

• The front windscreen must let at least 75% of light through.
• The front side windows must let at least 70% of light through.

Anything darker is not road legal, and if you’re involved in an accident, your insurer could argue the vehicle was illegally modified and therefore not covered.

Source: Tinted vehicle windows: the law – GOV.UK

Even if your tinted windows are legal, if they are a modification from the original spec of the car, your insurer needs to know about them.

Why Insurers Reject Claims Over Modifications

Insurers may reject a claim for a few key reasons:

1. Non-disclosure – If you fail to tell your insurer about a modification, they may consider it a breach of your policy terms.
2. Increased risk – Certain mods can increase the chance of theft and, speed-related accidents, or reduce vehicle safety.
3. Legality – If a modification breaks the law (like overly dark window tints), it may void your policy entirely.

This doesn’t just apply to big claims either. Even a minor accident could lead to a thorough investigation, and undeclared modifications can quickly come to light.

Here is our advice so you don’t get caught out:

• Be honest: Always disclose all modifications to your broker, even if they seem insignificant.
• Check the law: Make sure any planned changes are legal in your region.
• Get it in writing: If you speak to your broker about a mod over the phone, follow up with an email or ask for confirmation in writing.
• Check your documents: as above, make sure that your policy documents accurately reflect the disclosure you have made. Pay particular attention to the statement of fact
• Speak to the manufacturer: If you have purchased a vehicle second hand, you may not know if it’s been modified. Speak to the retailer for peace of mind.

Honesty is the best (insurance) policy

Modifying your car can be part of your passion or identity—but when it comes to insurance, transparency is key. Something as small as a set of tinted windows could mean the difference between a valid claim and a costly rejection. Always notify your insurer or broker of any changes, and make sure your car remains road legal to avoid nasty surprises down the line.