To help us provide you with free impartial advice, we may earn a commission if you buy through links on our site. Learn more

What Would Void a Car Warranty?

What would void a car warranty - featured. Close up of hands with a pen and clip board, assessing the state of a car. Car with open hood in background

Don’t get caught out when things go wrong - here's what can void a car warranty

Buying a new car can be exciting, but expensive. So, knowing that your vehicle is protected by a manufacturer warranty offers a much-needed level of reassurance, should things go awry.

But what happens if something does go wrong, and having returned to the manufacturer, you discover that your policy is invalid? Whether this is the result of unapproved modifications, a failure to keep your car properly serviced or annoying exclusions hidden in the warranty small print, there are a few scenarios of which you should be aware of when it comes to ensuring your vehicle has the right level of cover in place.

Below, we run through the top reasons that could cause your car warranty to become void, leaving you with unexpected repair bills and an expensive headache.

What is a car warranty?

No matter how reliable the brand from whom you’ve bought your car, it makes sense to check the warranty offered with your new purchase. Most cars come with a basic warranty that will cover most aspects of the vehicle’s system, such as air conditioning, engine and any tech; but it’s likely to exclude the parts that can suffer normal wear and tear, such as wipers and brake pads.

A basic warranty is likely to cover the first three or four years after purchase, or up to a certain number of miles – around 50,000 or so, but this will vary from one retailer to the next. Some vehicles’ warranties may also include breakdown cover, for example. It’s important to note that a warranty isn’t the same as insurance, which you should also organise to provide cover against scenarios such as fire, theft and flood, for instance. However, even with the most careful planning, all of these policies could become invalid if you make the all-too-common mistakes outlined below.

What would void a car warranty


As mentioned, most policies will state a maximum mileage for which it will cover the vehicle, and once this has passed, you’ll need to make your own arrangements. You should also be aware that some warranties will only protect vehicles under a certain average annual mileage. Note that altering or tampering with the car’s odometer in any way will automatically void your policy.


Many car enthusiasts enjoy tailoring their vehicle to their personal taste; think tinted windows, vanity plates, lowering the suspension and fitting additional exhausts or spoilers. However, it’s important to ensure that any modifications are performed within the parameters of the warranty, and by an approved garage using manufacturer-approved parts; otherwise, you could find yourself seriously out of pocket.

Fair wear and tear

Unfortunately, most warranties will not pay out if you’re unhappy with the longevity or performance of wearable items such as tires, headlights, wipers, pads and fabric or leather interiors. While “fair wear and tear” is always a gray area on which all parties would have to agree, it’s unlikely that your policy will cover these items, no matter how strong your argument.

READ NEXT: Average Miles Driven Each Year


The responsibility for ensuring your car is topped up with essentials such as engine oil, coolant and the right fuel – all of dealer-approved quality – is yours. Mistakenly adding diesel to your petrol car, or vice versa, can cause severe damage to your vehicle and your policy will immediately be void. Note that it’s also on you to regularly check tire pressure and adjust wheel alignment to keep your car running smoothly outside of any trips to the garage.

What would void a car warranty. Close up of a mechanic's hands as they pour coolant fluid in to car


Check your warranty and your vehicle’s capabilities when it comes to towing or loading heavy cargo, including passengers. Guidelines on towing and weight limits can be found in the manufacturer’s handbook. Exceeding the recommended weight will mean that you’re liable for all repairs.

READ NEXT: The 10 Most and Least Reliable Car Brands


It goes without saying that you’ll need to keep your vehicle’s service history up to date. Be sure to visit approved garages and keep the receipts. Don’t be tempted to use cheaper backstreet outfits that may not be recognised by your manufacturer.


Depending on the purposes for which your vehicle is designed, misuse such as off-road driving could invalidate your warranty, so stick to the highway. And watch your speed: racing isn’t only unsafe and illegal, but can quickly leave you out of pocket if you damage your vehicle while doing so.

Read more

In Depth