What is a car insurance group?
A car insurance group is a score from 1 to 50 that gives insurers a quick read on how risky a car is. Group 1 sits at the low risk end and group 50 at the high risk end.
It is one of those bits of insurance jargon you only meet when a quote lands. Your car insurance group is not a verdict on you or your driving, and it is not the price. It is one input among many.
The score is advisory, according to Thatcham Research, which handles the data behind it. Thatcham says the vehicle details that manufacturers supply go into its own database, and are passed to the ABI Group Rating panel every week. The panel uses them to set a rating for the vehicle.
How is a car insurance group worked out?
A car insurance group is worked out from the car, not the driver. Thatcham says the system reviews more than 125 data points, and lists several factors that sit behind the score.
- Cost: the repair strategy a car needs, plus the cost and time to put it right after a claim.
- Price: the new price of the car and the cost of settling a total loss.
- Performance: acceleration from 0 to 60, weight and top speed.
- Design: how complex the standard fit systems are, including security and active safety equipment.
- Features: an indicative view of the risk of the car compared with other vehicles.
Thatcham adds that parts pricing counts, using a standard list of the panels and components most often damaged in accidents. The standard fitment and performance of autonomous emergency braking is part of it too.
There is also a security suffix. Thatcham describes it as showing how well the vehicle performs against a benchmark set of security tests. So a rating can come with a suffix after the number, and that suffix is about security rather than speed or price.
Is the 1 to 50 car insurance group being replaced?
Yes, Thatcham says the 1 to 50 system is being replaced by a Vehicle Risk Rating model. Its group rating page describes the current system as being replaced by a more advanced and dynamic five assessment model, and does not set out what those five assessments are.
So the car insurance group you see today may not be the only way your car is rated for long. The page carries no published or last updated date, and no date for when the old scale stops, so treat any firm date you read elsewhere with caution.
For a driver, the practical point is small. A quote still comes down to the car, the person, the address and the cover, whichever scoring system sits behind it. Nobody can tell you what a group will cost you without a quote in front of them.
Does your car insurance group decide your premium?
No. A car insurance group is one factor, and insurers weigh it alongside things about you. Quotes vary by the driver, the car, where it is kept and the claims history, so two people with the same car can see quite different prices.
That is the line that matters most here. A low group does not guarantee a low quote, and a high group does not mean you are stuck with a high one. We cannot say what your premium will be, and no honest guide can.
What you can do is use the group as a starting point for questions. If you are choosing between two cars, or checking why a quote moved, the group is a fair thing to ask your insurer about. Because the rating is advisory, insurers can treat it differently.
The same goes if you change car. Because the rating takes in the new price of the vehicle and the complexity of its standard equipment, different versions of the same model can carry different ratings. Check the exact version, not just the model name, when you compare quotes.
If your renewal has gone up and you are wondering why, our guide to car insurance renewal prices sets out how renewals work. For the basics, we also have a short explainer on checking that your car is insured.
How do you find out your car insurance group?
Thatcham’s page explains how the rating is set, but it does not offer a lookup for drivers. The simplest route is to ask. When you get a quote, ask the insurer which group it used for your exact make, model and trim, because different versions of the same car can sit in different groups. If you are weighing up an electric car, our guide to electric car insurance covers the extra questions worth asking, such as how battery damage is treated.
How can you compare car insurance without guessing?
Put your own details in and compare like for like. The cover, the excess and the extras matter as much as the headline price, so line them up side by side before you decide.
We do not recommend a policy or an insurer here, and a comparison cannot promise a particular price. It can show you what is available for your details, which is a fair way to see where you stand.
Frequently asked questions about car insurance groups
- What is the highest car insurance group?
- The scale runs from 1 to 50, with 50 at the highest risk end. Thatcham describes the rating as advisory, so insurers do not have to follow it.
- Does a lower car insurance group mean cheaper insurance?
- Not on its own. The group is one factor, and quotes also depend on the driver, the car, the address and the claims history.
- What does the suffix after a car insurance group mean?
- Thatcham says it is a security suffix that shows how the vehicle performs against a benchmark set of security tests.
- Is the 1 to 50 group rating being replaced?
- Thatcham says it is being replaced by a five assessment Vehicle Risk Rating model, though its page does not give an end date for the old scale.
Sources
- Thatcham Research: Group Rating. The page carries no published or last updated date. Source of the 1 to 50 scale, the advisory status, the weekly supply of manufacturer data to the ABI Group Rating panel, the 125 data points, the cost, price, performance, design and features factors, the parts pricing list, autonomous emergency braking, the security suffix and the five assessment Vehicle Risk Rating model that will replace it.
Checked 10 November 2026.
