How Car Insurance Groups Work and Why They Matter

What Are Car Insurance Groups?

Every car model sold in the UK is assigned to an insurance group on a scale of 1 to 50. Group 1 represents the cheapest cars to insure, while group 50 represents the most expensive. The system exists to give insurers a standardised way to assess the likely cost of covering a particular vehicle.

The grouping is not something individual insurers decide — it is set centrally by the Group Rating Panel, which is made up of members from the Association of British Insurers (ABI) and Thatcham Research, the motor insurers' automotive research centre. Every new car that goes on sale in the UK is assessed and assigned a group before it reaches showrooms.

When you request a car insurance quote, the insurer uses the car's group rating as one of several factors to calculate your premium. A car in group 5 will almost always be cheaper to insure than one in group 35, all other things being equal.

Why Do Insurers Use Group Ratings?

The insurance group system was introduced to create consistency. Without it, every insurer would need to independently assess every make, model, and variant of every car — an impractical task given the thousands of vehicles on UK roads.

The group rating gives insurers a shortcut. It distils a car's likely insurance risk into a single number based on objective, measurable criteria. This means:

• Quotes are more accurate — they reflect the real-world cost of repairing or replacing that specific car.
• Consumers can compare — you can look up insurance groups before buying and factor insurance cost into your decision.
• The system is transparent — the criteria used to set groups are publicly available.

That said, the insurance group is not the only factor in your premium. Your age, driving experience, postcode, job title, annual mileage, and claims history all play a part. But the car's group rating sets the baseline for the vehicle element of the cost.

How the UK Insurance Group System Works

The 1–50 scale is straightforward in principle. Cars in lower groups are statistically cheaper and less risky to insure. Cars in higher groups cost more to repair, are more powerful, or are more likely to be stolen.

Here is a general breakdown:

Groups 1–10: Low Cost to Insure

These are typically small, low-powered cars with modest performance and cheap parts. They are ideal for new drivers, young drivers, and anyone looking to minimise insurance costs.

Examples include the Volkswagen Up, Fiat 500 (basic trim), Skoda Fabia, Toyota Aygo, and Dacia Sandero.

Groups 11–25: Moderate Cost to Insure

This range covers the majority of mainstream family cars, medium-sized hatchbacks, and popular SUVs. Performance is moderate, parts are readily available, and safety features are generally good.

Examples include the Ford Focus, Vauxhall Astra, Nissan Qashqai, Kia Sportage, and Volkswagen Golf (standard trims).

Groups 26–40: Higher Cost to Insure

Cars here tend to be larger, more powerful, or fitted with expensive technology. Repair costs are higher, and some models may have elevated theft rates.

Examples include the BMW 3 Series, Audi A4, Mercedes C-Class, Tesla Model 3, and performance variants of popular models.

Groups 41–50: Most Expensive to Insure

These are high-performance sports cars, luxury vehicles, and rare or exotic models where repair and replacement costs are very high. Parts may be specialist, labour costs elevated, and theft risk significant.

Examples include the Porsche 911, BMW M3, Mercedes-AMG models, Range Rover Sport, and Audi RS models.

What Factors Affect a Car's Insurance Group?

The Group Rating Panel assesses every car against a set of defined criteria. Understanding these helps explain why seemingly similar cars can sit in very different groups.

Repair Costs

This is the single biggest factor. Thatcham Research carries out standardised crash tests on every new car and calculates how much it would cost to repair damage from low-speed impacts (both front and rear). Cars that are expensive to fix — because of complex body panels, integrated sensors, or specialist materials — are placed in higher groups.

A car with a bumper that costs £150 to replace will sit lower than one with a bumper housing parking sensors, cameras, and radar units that costs £1,500.

Parts Prices

The cost of replacement parts — including body panels, windscreens, headlights, and mechanical components — directly affects the group rating. Cars with cheaper, widely available parts score better. Those requiring manufacturer-specific or imported components score worse.

This is one reason why some budget-friendly cars have surprisingly high insurance groups — if their parts are expensive or hard to source, repair costs climb.

Vehicle Performance

Acceleration, top speed, and engine power all influence the group rating. Faster, more powerful cars are statistically more likely to be involved in high-speed accidents, and the severity of those accidents tends to be greater.

A 1.0-litre hatchback and its 2.0-litre turbocharged equivalent may look identical from the outside, but the performance variant will sit in a significantly higher insurance group.

Safety Features

Cars with strong safety records are rewarded with lower group ratings. The panel considers:

• Euro NCAP crash test ratings — higher star ratings help lower the group.
• Autonomous emergency braking (AEB) — this feature can reduce the group rating by several points.
• Other active safety systems — lane departure warning, blind-spot monitoring, and adaptive cruise control can all have a positive effect.

A car with a five-star Euro NCAP rating and AEB may sit several groups lower than a similar car without those features.

Theft Rates

If a particular model is disproportionately targeted by thieves, its insurance group may be increased. The panel reviews real-world theft data and considers how easy a car is to break into or steal.

Cars with poor security — such as those vulnerable to keyless entry relay attacks — may receive higher ratings. Conversely, models with strong anti-theft technology (immobilisers, tracking devices, Thatcham-approved alarms) score better.

Bumper Compatibility

Thatcham assesses how well a car's bumpers absorb low-speed impacts and protect the structure behind them. Cars with bumpers that limit damage in minor collisions — reducing repair costs — are placed in lower groups.

Why Insurance Groups Matter for Buyers

If you are choosing a car and insurance cost is a concern — and for most people it should be — the insurance group is one of the first things to check. Two cars at the same price on the forecourt can have wildly different insurance costs depending on their group rating.

For example, a Volkswagen Polo in group 6 and a MINI Cooper S in group 25 might cost a similar amount to buy. But the MINI could be hundreds of pounds more expensive to insure each year, especially for younger drivers. Over the lifetime of ownership, this difference adds up significantly.

Checking the insurance group before you buy ensures there are no nasty surprises when you go to get a quote.

How Insurance Groups Affect Young Drivers

For drivers aged 17–25, the insurance group has a disproportionately large effect on premiums. Young drivers already face the highest insurance costs due to their lack of experience and higher statistical accident risk. Adding a high-group car on top of that can make insurance unaffordable.

A young driver insuring a group 3 Citroën C1 might pay £1,200 per year. The same driver insuring a group 20 Volkswagen Golf could pay £2,500 or more. And a group 35 BMW? Potentially £4,000+.

This is why most driving instructors and car-buying guides recommend that young drivers stick to groups 1–10 for their first car. The savings are substantial, and they can build up a no-claims bonus that brings costs down over time.

Tips for Young Drivers Choosing a Car

• Target insurance groups 1–10 — these give you the lowest possible vehicle-related premium.
• Choose cars with smaller engines — 1.0-litre or 1.2-litre petrol engines are ideal.
• Avoid modifications — any aftermarket changes (alloy wheels, sports exhausts, lowered suspension) can push up your premium even if the base car is in a low group.
• Consider a telematics (black box) policy — these monitor your driving and can significantly reduce costs for safe drivers.

How to Check a Car's Insurance Group

Checking a car's insurance group is free and takes seconds. You can do it before visiting a seller, before placing a bid at auction, or while browsing online listings.

Online Lookup Tools

Several websites allow you to enter a car's registration number or its make and model to see the insurance group. Thatcham Research's own tool is the most authoritative source, as they are the organisation that sets the ratings.

Ask the Insurer

When you get a quote, the insurer will tell you the group rating of the car. If you are comparing multiple vehicles, get quotes for each and note the difference.

Check the V5C and Listing Details

Some online car listings include the insurance group. The V5C does not show the group directly, but it confirms the exact model variant — which you can then look up.

Choosing a Car With Lower Insurance Costs

If keeping insurance affordable is a priority, here is how to approach car shopping:

1. Research insurance groups first. Before you fall in love with a particular car, check what group it sits in. A few minutes of research can save hundreds of pounds a year.
2. Compare variants carefully. The same model in different trims or engine sizes can span 10 or more insurance groups. A Ford Fiesta 1.0 might be in group 6, while the Fiesta ST sits in group 27.
3. Prioritise safety features. Cars with AEB, lane assist, and high Euro NCAP ratings tend to sit in lower groups relative to their size and power.
4. Check parts availability. Popular, mainstream cars have cheaper and more available parts, which keeps repair costs — and insurance groups — lower.
5. Avoid high-theft models. Some cars are targeted more often by thieves. Check theft statistics and consider cars with strong security features.

Key Tips for Keeping Insurance Affordable

Beyond choosing a car in a lower group, there are several other steps that help reduce your premium:

• Build a no-claims bonus. Every claim-free year reduces your premium. Protect your no-claims bonus once you have several years built up.
• Increase your voluntary excess. Agreeing to pay a higher amount in the event of a claim reduces your annual premium — but make sure you can afford the excess if you need to claim.
• Limit your mileage. Lower annual mileage means lower risk, which means a lower premium. Be honest — underestimating mileage can invalidate your policy.
• Improve security. Parking in a locked garage, fitting a Thatcham-approved alarm, or installing a tracking device can all help.
• Shop around every year. Loyalty rarely pays with car insurance. Compare quotes from multiple providers at renewal time.
• Consider a telematics policy. Black box insurance monitors your driving and rewards safe behaviour with lower premiums. This is especially effective for younger drivers.

Insurance Groups and Electric Cars

Electric vehicles (EVs) present an interesting case. While they have fewer mechanical components and lower running costs, their insurance groups can be surprisingly high. This is because:

• Battery replacement is very expensive — a damaged battery pack can cost thousands to replace.
• Specialist repair skills are needed — not all garages can work on high-voltage EV systems.
• Parts are often manufacturer-specific — there is less aftermarket availability.
• Some EVs are very powerful — electric motors deliver instant torque, which can increase accident severity.

However, as the EV market matures and repair infrastructure improves, insurance groups for electric cars are expected to stabilise and potentially decrease.

The Difference Between Insurance Group and Insurance Cost

It is worth noting that the insurance group is not the same as your insurance premium. The group tells you how expensive the car element of your insurance is likely to be — but the final price also depends on:

• Your age and driving experience
• Your postcode and where the car is kept
• Your occupation
• Your claims and conviction history
• The level of cover you choose (third party, third party fire and theft, or comprehensive)
• Your voluntary excess
• Any additional drivers on the policy

Two people insuring the same group 15 car could pay very different premiums based on these personal factors. The insurance group is a starting point, not the final answer.