Car Modifications and Insurance: What to Declare
Updated Oct 1, 2026 · Hannah Breckett · 5 min read
Even small changes like alloy wheels or tinted windows may need declaring.
What this article covers
Modifications can change how a car performs, how attractive it is to thieves, and how much repairs cost.
Failing to declare them can invalidate your insurance.
Common modifications
- Alloy wheels
- Tinted windows
- Body kits and spoilers
- Engine remaps
- Lowered suspension
- Tow bars and roof racks
Why insurers care
Performance changes can increase accident risk. Cosmetic changes can increase theft risk or repair costs.
Safety modifications
Some modifications, like dashcams or approved security systems, may lower premiums. Disability adaptations are often treated differently.
Tell your insurer
Declare changes when buying or as soon as made. Keep receipts. Some insurers specialise in modified cars.
Buying a modified car
If you buy a used car that has already been modified, you still need to declare those modifications, even though you did not make them. Ask the seller for a full list and receipts. Some changes — such as engine remaps — are not always obvious, so a pre-purchase inspection can help. Not knowing about a modification is unlikely to be accepted as a reason for non-disclosure if you make a claim.
This is general insurance information, not legal, financial, or insurance advice. Coverage depends on your specific policy, insurer, and jurisdiction. Read your policy documents and speak with a licensed insurance agent or broker before making decisions.