Every car sold in the UK is placed into one of 50 insurance groups, and that grouping directly affects how much you pay for cover. Group 1 is the cheapest to insure and Group 50 is the most expensive. Understanding how the system works can help you choose a car that costs less to insure - or make sense of why your current premium is what it is.
Car insurance groups are a rating system that helps UK insurers assess how much a particular car is likely to cost them in claims. Every car is assigned a group from 1 (cheapest to insure) to 50 (most expensive) based on factors like how much it costs to repair, how powerful it is, and how secure it is.
The system is run by Thatcham Research, a not-for-profit organisation, on behalf of the Association of British Insurers (ABI). A panel of industry experts meets every month to assign groups to new car models as they come to market.
Until 2009, there were only 20 groups. The expansion to 50 allows each car to be rated more precisely, giving insurers and drivers a clearer picture of how a specific model compares to others.
The Group Rating Panel looks at several factors when deciding which group a car belongs to. The single biggest factor is how much the car costs to repair after an accident.
| Factor | Why it matters |
|---|---|
| Repair costs | Most claims involve repairs rather than write-offs. Thatcham tests crash damage at 15km/h and assesses parts costs and labour time. Cars with expensive or hard-to-source parts go into higher groups. |
| Vehicle value | More expensive cars cost more to repair or replace. However, a costly car with cheap parts can sit in a lower group than a cheaper car with specialist components. |
| Performance | Acceleration, top speed, and engine power all affect grouping. Higher-performance cars are statistically more likely to be involved in accidents and cause more damage. |
| Safety features | Cars with advanced safety tech like Autonomous Emergency Braking (AEB) can be moved into lower groups because they reduce the chance and severity of accidents. |
| Security | Vehicle theft is a major source of claims. Cars with strong security features (alarms, immobilisers, anti-theft tech) can drop groups, while those with poor security may be pushed higher. |
Two cars at the same price can sit in very different groups. A car designed for easy, affordable panel replacement will always be cheaper to insure than one that needs specialist parts or lengthy labour. This is one reason why some small SUVs cost more to insure than you might expect.
You will often see a letter after your car's insurance group number - for example, 15E, 10A, or 8D. This letter is a security suffix that tells you how the car's security compares to what Thatcham expects for a vehicle of that type. It can raise or lower the group rating, which affects your premium.
If your car is rated 15E, for example, it means it was originally assessed at Group 15 but has better security than expected, so it has been moved down a group. A car rated 15D has been moved up because its security falls short. The letter A means the car meets the expected standard with no adjustment.
| Letter | Meaning | Effect on your insurance |
|---|---|---|
| E | Exceeds security requirements | Group rating reduced - the car has better security than expected, which can mean a lower premium |
| A | Acceptable | Meets the expected security standard for its group - no adjustment made |
| D | Does not meet requirements | Group rating increased - poorer security than expected, which can push your premium up |
| P | Provisional | Not enough data available yet - the rating may change once Thatcham has fully assessed the car |
| G | Grey import | Not officially sold in the UK - Thatcham cannot rate it, so the insurer sets the price individually |
| U | Unacceptable security | Serious security concerns - some insurers may refuse cover or require upgraded security before agreeing to insure |
When comparing two similar cars, always check the security suffix. A car rated 10E will typically cost less to insure than one rated 10A or 10D, because the E means it has been moved down a group for exceeding security standards. Looking for cars with an E suffix is a simple way to find lower premiums.
Here is a broad overview of what each range of insurance groups covers and the types of car you will typically find in each.
| Groups | Typical cars | Who they suit |
|---|---|---|
| 1-10 | Hyundai i10, Kia Picanto, VW Up!, Toyota Aygo, Skoda Fabia | Small engines, affordable parts, ideal for young drivers and anyone looking for the cheapest cars to insure |
| 11-20 | VW Golf (base), Ford Focus, Vauxhall Astra, Nissan Qashqai | Mid-range family cars with moderate performance and reasonable repair costs - a good balance of features and insurance cost |
| 21-30 | BMW 3 Series, Audi A4, Mercedes C-Class, Golf GTI | Premium brands and higher-performance variants with more expensive parts - premiums noticeably higher than Groups 1-20 |
| 31-40 | BMW M Sport, Range Rover Sport, performance SUVs | High-value cars with powerful engines and specialist parts - substantial insurance costs and higher theft risk |
| 41-50 | BMW M3/M5, Porsche 911, Nissan GT-R, Mercedes-AMG | High-performance sports cars with very expensive repairs - often need specialist cover. See our performance car insurance page |
If keeping insurance costs low is a priority, choosing a car in Groups 1 to 5 can save you hundreds of pounds a year. These are typically small, low-powered cars with good safety ratings and affordable parts. Here are some of the most popular models in the lowest groups.
| Car | Typical group | Notes |
|---|---|---|
| Hyundai i10 1.0 | Group 1 | Excellent reliability, 5-year warranty |
| Kia Picanto 1.0 | Group 1-2 | 7-year warranty on new models |
| Volkswagen Up! 1.0 | Group 1 | Premium feel, reliable engineering |
| Toyota Aygo X 1.0 | Group 1-3 | Exceptional reliability record |
| Skoda Fabia 1.0 | Group 2-3 | More space than city cars, practical boot |
| Volkswagen Polo 1.0 | Group 2-3 | Quality interior, refined to drive |
| Fiat Panda 1.0 | Group 1-3 | Affordable to buy and run |
| Renault Clio 1.0 | Group 3-5 | Good fuel economy, stylish design |
The same model can span many insurance groups depending on engine size and trim. A Volkswagen Polo 1.0 in basic trim sits in Group 3, while a Polo 2.0 TSI GTI jumps to Group 25. Always check the exact variant you are considering. For a deeper look, see our guide on the cheapest cars to insure in the UK.
Your car's insurance group is one of the factors you have the most control over. Here are the key ways to use the system to your advantage.
Check the insurance group before buying any car. This is the single most effective step. A small hatchback in Group 1 could cost half as much to insure as one in Group 10, and for young drivers the difference can run into the hundreds or even thousands of pounds.
Choose a lower-powered variant if you like a particular model. The base Ford Fiesta 1.1 sits in Group 6, while the sporty Fiesta ST jumps to Group 29. Optional extras like larger alloy wheels or an upgraded engine can also push a car into a higher group. Our guide on how modifications affect car insurance explains this in more detail.
Look for cars with an E security suffix. A car rated 10E has been moved down a group because its security exceeds expectations, which typically means a lower premium than the same car rated 10A or 10D.
Consider adding approved security to an older car. Fitting a Thatcham-approved alarm or tracking device will not change the official group rating, but many insurers factor approved security into their pricing and it could reduce your premium. A dash cam can also help protect your no claims bonus by providing evidence in the event of a claim.
Compare quotes from multiple insurers. Insurers are not required to follow Thatcham's group ratings exactly - they use them as a guide alongside their own data. This is why quotes can vary by hundreds of pounds for the same car. Comparing car insurance quotes via Brumble lets you search across 130+ insurers in minutes.
The Vehicle Risk Rating (VRR) is a new system launched by Thatcham Research in September 2024 that applies to newly registered cars. Instead of a single 1-50 group, VRR scores each car from 1 (low risk) to 99 (high risk) across five separate categories: performance, damageability, repairability, safety, and security.
The aim is to give insurers a more detailed picture of each car's risk profile, particularly for modern vehicles with complex electronics and advanced driver assistance systems.
VRR only applies to cars first registered from 1 August 2024 onwards. If you are buying a used car, insuring your current vehicle, or looking at a nearly-new car registered before that date, the traditional 1-50 group system still applies. Both systems are running in parallel until early 2027. After that, VRR becomes the sole reference for new cars, but the 1-50 groups will remain in use for the entire used car market for many years to come.
Group 1 is the cheapest car insurance group. Cars in this category include the Hyundai i10, Kia Picanto, and Volkswagen Up!. They have small engines, low performance, and affordable repair costs. For a full list, read our guide on the cheapest cars to insure.
15E means your car was assessed at insurance Group 15 but has better security than expected for that type of vehicle. The E stands for "exceeds requirements", which means the car has been moved down a group, potentially lowering your premium compared to a car rated 15A or 15D.
You can check your car's insurance group using the Thatcham Research website. Enter your car's make, model, and variant to find its group rating. Your car's documentation or V5C logbook reference may also help you identify the exact variant to look up.
Modifications do not officially change your car's assigned insurance group, but they can significantly affect your premium. Any changes - from alloy wheels to engine tuning - must be declared to your insurer. Our guide on car modifications and insurance costs explains what you need to know.
Electric cars are often placed in higher groups than similar-sized petrol cars because they currently cost more to repair and parts can be harder to source. However, this varies by model and is expected to improve as the EV repair sector grows. Read our electric car insurance cost guide for more detail.
Not automatically. The official group assigned by Thatcham stays the same for the life of the car. However, as a car loses value and parts become cheaper and more available, some insurers may price it more favourably even though the group has not changed.
No. Insurers also consider your age, driving experience, claims history, where you live, your annual mileage, and the level of cover you choose. Our guide on how to lower your car insurance premium covers all the main factors and what you can do about each one.
The Vehicle Risk Rating system applies only to cars first registered from August 2024 onwards. Both systems are running in parallel until early 2027. After the transition, VRR becomes the sole reference for new cars, but the traditional 1-50 groups will remain in use for any car registered before August 2024.
Thatcham Research - Vehicle Risk Rating System
Thatcham Research - Group Rating Panel Guidelines
Association of British Insurers - Motor Insurance Premium Tracker
Head to the home page to compare quotes for car, van or motorbike insurance.
Compare QuotesGet the latest guides and motoring tips straight to your inbox.
EV Zone
