How Are Car Insurance Groups Calculated?
Car insurance groups are calculated by Thatcham Research, a not-for-profit automotive risk intelligence organisation, and reviewed by the ABI Group Rating Panel. Every car sold in the UK is assigned a group from 1 (cheapest to insure) to 50 (most expensive) based on repair costs, safety features, security, and performance.
Your car’s insurance group is one of the biggest factors in your premium. Understanding how groups work helps you make smarter choices when buying a car.
Our breakdown of car insurance costs explains all the factors insurers use, and group rating is among the most influential.
Thatcham Research scores every model from 1 to 50 on repair costs, performance, security and parts prices.
Compare car insurance quotes and check the group before you buy, not after.
What do the insurance group numbers mean?
Group 1 cars are the cheapest to insure, and group 50 the most expensive. The rating reflects how much a car costs an insurer to cover, based on repair bills, theft risk, and accident severity.
How are the 50 groups split?
| Group range | Typical vehicles | Example models |
| 1-10 | Small city cars, low-powered hatchbacks | Fiat Panda, Volkswagen Up, Hyundai i10 |
| 11-20 | Mid-range family cars, popular hatchbacks | Ford Focus, Vauxhall Corsa, Kia Ceed |
| 21-35 | Larger family cars, SUVs, entry-level premium | BMW 1 Series, Audi A3, Nissan Qashqai |
| 36-50 | High-performance, luxury, sports cars | BMW M3, Mercedes-AMG, Porsche 911 |
Is the group rating tied to the car or the driver?
The group is tied to the car model and does not change based on who drives it. Your personal factors (age, experience, postcode, claims history) are assessed separately on top of the group rating.
What factors does Thatcham Research use?
Thatcham assesses every new vehicle model using repair costs, parts prices, safety performance, security features, and vehicle performance. The Association of British Insurers Group Rating Panel then reviews and approves the rating before the car goes on sale.
Which factor carries the most weight?
Repair costs. A car that is cheap to fix after a typical low-speed collision will sit in a lower group than one with expensive body panels, specialist parts, or complex electronics.
Parts prices, labour rates, and the availability of replacement panels all feed into this calculation. Cars with widely available parts from multiple suppliers score better than those requiring manufacturer-only components.
How do safety and security affect the rating?
Cars with strong Euro NCAP crash test ratings and advanced driver assistance systems (autonomous emergency braking, lane keeping) tend to sit in lower groups because they reduce accident severity.
Security is assessed separately using a suffix system: E (exceeds requirements), A (acceptable), D (does not meet requirements), U (unacceptable). A poor security rating can push a car one or two groups higher.
How do insurance groups affect your premium?
Moving from a lower to a higher group can add hundreds of pounds per year. The difference between insuring a group 5 car and a group 30 car is substantial, even for the same driver in the same postcode.
Can you use groups to save money?
Checking a car’s insurance group before buying is one of the most effective ways to control costs. Our tips to lower your premium cover the full range of strategies, but choosing a lower group is the foundation.
This matters most for young drivers, who face the highest premiums. A young driver in a group 3 car can pay hundreds less than the same driver in a group 25 car.
What is the new Vehicle Risk Rating system?
From 2024, Thatcham Research is transitioning from the traditional 1-50 groups to a Vehicle Risk Rating (VRR) model that scores vehicles across five categories, each rated from 1 to 99.
What are the five VRR categories?
Performance covers engine power, acceleration, and top speed. Damageability measures how susceptible the vehicle is to damage in a collision.
Repairability assesses how expensive and complex repairs are. Safety covers crash protection and driver assistance systems.
Security rates theft resistance, immobiliser quality, and key security.
Will the old system disappear?
The traditional 1-50 system remains in widespread use during the transition. Insurers are adopting VRR at different speeds, so you may see both referenced when comparing quotes.
When comparing car insurance quotes, the underlying group or VRR score is the same across all providers. The difference is how each insurer prices on top of that baseline.
Can you change your car’s insurance group?
No, the group is fixed by Thatcham Research when the car model is released and does not change. Aftermarket modifications do not alter the group rating.
Do modifications affect your premium separately?
Yes. Modified cars must be declared to your insurer, and the modifications are priced separately from the group rating.
Adding a turbo or lowering the suspension will not change the group, but it will increase your premium.
Do security upgrades help?
Adding a Thatcham-approved tracker or immobiliser will not change the group, but some insurers offer separate discounts for approved security devices. A black box policy can also reduce premiums by rewarding safe driving, regardless of the car’s group.
Are electric cars in higher insurance groups?
It depends on the model. Electric cars are assessed using the same criteria as petrol and diesel vehicles, but battery replacement costs and specialist repair requirements can push some EVs into higher groups.
Which electric cars have lower groups?
Affordable EVs like the MG4, Fiat 500e, and Renault Zoe sit in mid-range groups (typically 15-25). Premium EVs like the Tesla Model S or BMW iX sit in groups 40-50.
As EV repair infrastructure improves and battery costs fall, groups for electric models are expected to decrease over time. Our guide to vehicle insurance covers the legal requirements for insuring any vehicle, including EVs.
Frequently Asked Questions (FAQs)
Search by registration number or make and model on the Thatcham Research website or any major comparison site. The group is publicly available for every car sold in the UK.
Yes, all UK insurers use Thatcham Research group ratings as a baseline. However, each insurer applies their own pricing on top, so quotes for the same group can vary between providers.
No, the group is fixed for the model as released. Aftermarket additions are assessed separately by your insurer and may qualify for discounts but will not change the group rating.
Group 1 is the cheapest. Cars in this group include small city cars like the Fiat Panda, Volkswagen Up, and Hyundai i10 with low-powered engines and cheap parts.
The group stays the same regardless of a car’s age, so a 2015 Ford Focus is in the same group as a brand-new one of the same specification. However, the car’s lower value may reduce your premium separately.
No, the new Vehicle Risk Rating system applies to new models going forward. Existing cars retain their 1-50 group ratings, and both systems run in parallel during the transition.