Key takeaway: Every car in the UK is assigned an insurance group from 1 (cheapest) to 50 (most expensive). The group is based on repair costs, performance, safety, and security. Moving from a Group 20 car to a Group 5 car can save £500 to £1,500 per year on insurance, depending on your age, location, and driving history.
Car insurance groups are one of the most important factors in determining your premium, yet most people have no idea what group their car falls into until they get a quote. Understanding the system gives you a real advantage when choosing your next car, because you can factor in the insurance cost before you buy, not after.
This guide explains how the groups work, what determines which group a car is placed in, gives examples across all 50 groups, and shows you how to check the group for any specific car. For a detailed breakdown of any car's insurance group alongside its full running costs, enter the registration number in our free tool.
Insurance groups are determined by the Group Rating Panel, a joint body run by the Association of British Insurers (ABI) and the Lloyds Market Association (LMA). They assess every new car model before it goes on sale and assign a group from 1 to 50. The assessment is based on these factors:
1. Damage and Parts Costs (Biggest Factor)
This is the single most influential factor. The panel looks at how much it costs to repair the 23 most commonly damaged parts (bumpers, wings, headlights, bonnet, etc.) and how long the repair takes. Cars with cheap, widely available parts score lower. Cars with expensive, dealer-only or imported parts score higher. This is why a VW Up (Group 1) uses cheap, universal parts, while a BMW i4 (Group 32) uses expensive, model-specific components.
2. New Car Value
Higher value cars cost more to replace if written off, so they sit in higher groups. A £10,000 Dacia Sandero and a £40,000 BMW 3 Series have very different replacement costs, which is directly reflected in their insurance groups.
3. Performance
Top speed and acceleration (0-62 mph time) are factored in. Faster cars are statistically more likely to be involved in accidents, and accidents at higher speeds cause more damage. This is why a 1.0-litre VW Up (Group 1) and a 2.0-litre Golf GTI (Group 29) sit in very different groups despite both being Volkswagens.
4. Safety (Euro NCAP Rating)
Cars with strong safety ratings (4 or 5 stars from Euro NCAP) receive a group reduction because their occupants are less likely to suffer serious injuries. Autonomous Emergency Braking (AEB) is particularly valued. Cars that score well for pedestrian safety also benefit.
5. Security (Thatcham Rating)
The panel assesses resistance to theft. Cars with factory-fitted immobilisers, alarms, and tracking systems score better. Cars that are easy to steal or are frequently targeted by thieves (certain BMW, Range Rover, and Ford models) may be placed in higher groups.
6. Bumper Compatibility
Cars designed to absorb low-speed impacts without expensive damage score better. This is tested using standardised low-speed crash tests. Cars where a minor parking bump costs £2,000 in sensors and paint (common in modern luxury cars) are penalised.
You can check the insurance group for any specific car on our insurance groups page, which lists every group with example cars and typical costs.